Cooling apparatus, electronic apparatus, and blower apparatus

ABSTRACT

Disclosed is a cooling apparatus including a heat sink, a blower mechanism, an opening member, and a movement mechanism. The blower mechanism has a blower opening that has a predetermined area and is opposed to the heat sink. The opening member has a first opening that has an area smaller than the area of the blower opening. The movement mechanism moves the opening member so that switching between a first state and a second state is performed. The first state is a state in which the first opening is disposed between the blower opening and the heat sink, and the second state is a state in which the first opening is removed from between the blower opening and the heat sink.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2008-246645 filed in the Japan Patent Office on Sep. 25, 2008 and Japanese Priority Patent Application JP 2009-002337 filed in the Japan Patent Office on Jan. 8, 2009, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present invention relates to a blower apparatus that generates airflow to a heat sink, a cooling apparatus including a heat sink and a blower apparatus, and an electronic apparatus equipped with a cooling apparatus.

In the past, with increase in performance of a PC (personal computer), the amount of heat generated from a heat source such as a CPU has problematically increased. To deal with this problem, various techniques of radiating heat have been proposed or produced. There has been known a heat radiation method in which heat from a CPU is transferred to a heat sink including radiation fins made of a metal such as aluminum and is radiated from the radiation fins, thereby forcibly getting rid of warmed air around the radiation fins by using a fan apparatus.

However, the fan apparatus takes in air around the fan apparatus from an intake and blows the air to the radiation fins of the heat sink. Therefore, the fan apparatus undesirably blows dirt or dust contained in the air to the radiation fins together. As a result, the dust adheres to gaps of the radiation fins and accumulates thereon, which causes a problem of degrading a cooling performance of the heat sink.

As a technique relating to the above problem, Japanese Patent Application Laid-open No. 2005-321287 (paragraphs 0035, 0050, 0062, and 0063, and FIG. 1) (hereinafter, referred to as Patent Document 1) discloses a cooling apparatus provided with a trapezoidal heat sink having an incline portion on an end surface on a side to which airflow generated by the rotation of a blade portion is directed. To a duct that regulates airflow generated by the blade portion into one direction, a dust outlet is provided in addition to an intake and an outlet. The dust contained in the airflow is transferred along the incline portion of the heat sink and is put out to outside from the dust outlet provided to the duct.

In addition, as a technique relating to the above problem, Japanese Patent Application Laid-open No. 2008-159925 (paragraphs 0036, and 0042 to 0045, and FIGS. 3 and 4) (hereinafter, referred to as Patent Document 2) discloses a cooling apparatus provided with a heat sink including a first heat sink and a second heat sink that are separately formed. The second heat sink which is provided close to a blower opening of a cooling fan and to which dust easily adheres is detachably incorporated in an electronic apparatus such as a PC. A user detaches the second heat sink from the PC and washes it, to remove the accumulated dust from the second heat sink.

SUMMARY

However, the cooling apparatus disclosed in Patent Document 1 does not sufficiently overcome the above problem of removing the dust, although the cooling apparatus can reduce the amount of dust that adheres to the heat sink. With increasing utilization of the PC, the dust accumulates between the radiation fins in the end.

On the other hand, in the cooling apparatus disclosed in Patent Document 2, the second heat sink can be detached from the PC and washed. However, in the cooling apparatus, the user has to detach the second heat sink from the PC, which is a troublesome task.

In view of the above-mentioned circumstances, it is desirable to provide a blower apparatus capable of automatically removing the dust that adheres to a heat sink, a cooling apparatus including the blower apparatus and the heat sink, and an electronic apparatus equipped with the cooling apparatus.

According to an embodiment, there is provided a cooling apparatus including a heat sink, a blower mechanism, an opening member, and a movement mechanism.

The blower mechanism has a blower opening that has a predetermined area and is opposed to the heat sink.

The opening member has a first opening that has an area smaller than the area of the blower opening.

The movement mechanism moves the opening member to perform switching between a first state and a second state. The first state is a state in which the first opening is disposed between the blower opening and the heat sink, and the second state is a state in which the first opening is removed from between the blower opening and the heat sink.

In this embodiment, in the first state, the first opening of the opening member is located between the blower opening and the heat sink. Because the first opening has the area smaller than that of the blower opening, the area of the blower opening can be temporarily made smaller by using the first opening. As a result, it is possible to locally increase a flow rate of airflow flown out from the blower opening. Thus, the dust that adheres to and accumulates on the heat sink can be removed (dust removal mode).

On the other hand, in the second state, the first opening of the opening member is not located between the blower opening and the heat sink. Therefore, in the second state, the airflow is directed to the heat sink from the entire blower opening, thereby cooling the heat sink (cooling mode).

Further, in this embodiment, the first state (dust removal mode) and the second mode (cooling mode) can be automatically switched by the movement mechanism, with the result that a troublesome task of detaching the heat sink from an electronic apparatus such as a PC and washing it can be eliminated.

In the cooling apparatus, the opening member may further have a second opening having an area approximately equal to the area of the blower opening.

In this case, the second state may be a state in which the second opening is opposed to the blower opening.

In this embodiment, in the second state, the second opening having the area approximately equal to the area of the blower opening is opposed to the blower opening. Through the second opening, the airflow is directed to the heat sink from the entire blower opening, thereby cooling the heat sink.

In the cooling apparatus, the opening member may be a band-like member having a longitudinal direction.

In this case, the first opening and the second opening may be formed in the band-like member in a line along the longitudinal direction of the band-like member.

Further, in this case, the movement mechanism may move the band-like member along the blower opening in the longitudinal direction.

In this embodiment, the switching between the first state and the second state is performed by moving the band-like member having the first opening and the second opening in the longitudinal direction of the band-like member. In this case, the band-like member is moved along the blower opening, and therefore the first opening and the second opening are also moved along the blower opening. When the first opening is moved along the blower opening, a position at which strong airflow is generated is moved along the blower opening. As a result, the strong airflow can be directed to the entire heat sink opposed to the blower opening, which can remove the dust from the entire heat sink.

In the cooling apparatus, the movement mechanism may include a first shaft, a second shaft, and a drive source.

The first shaft is connected to an end portion of the band-like member and capable of rolling up and rolling out the band-like member.

The second shaft is disposed so that the first shaft and the second shaft sandwich the blower opening, connected to another end portion of the band-like member, and capable of rolling up and rolling out the band-like member.

The drive source rotates and drives the first shaft and the second shaft.

In this embodiment, because the first shaft and the second shaft can roll up and roll out the band-like member, it is possible to reduce a space in which the band-like member is provided. As a result, the cooling apparatus can be downsized.

In the cooling apparatus, the band-like member may be annular.

In this case, the movement mechanism may include a plurality of shafts and a drive source.

The plurality of shafts support the band-like member while rotating the band-like member around the blower mechanism with the plurality of shafts being provided around the blower mechanism.

The drive source rotates and drives at least one of the plurality of shafts.

In this embodiment, because the band-like member rotates around the blower mechanism, the space in which the band-like member is provided can be reduced, with the result that the cooling apparatus can be downsized.

In the cooling apparatus, the opening member may be a plate-like member having a longitudinal direction.

In this case, the movement mechanism may move the plate-like member along the blower opening in the longitudinal direction.

In this embodiment, the plate-like member having the first opening is moved along the blower opening, and therefore the first opening is also moved along the blower opening. When the first opening is moved along the blower opening, a position at which strong airflow is generated is moved along the blower opening. As a result, the strong airflow can be directed to the entire heat sink opposed to the blower opening, which can remove the dust from the entire heat sink.

In the cooling apparatus, the plate-like member may include a rack gear in the longitudinal direction.

In this case, the movement mechanism may include a pinion and a drive source.

The pinion is engaged with the rack gear.

The drive source rotates and drives the pinion.

In this embodiment, with the use of the rack and pinion mechanism, the plate-like member is linearly moved and the first opening is moved between the heat sink and the blower opening. As a result, the dust that adheres to and accumulates on the heat sink can be removed with the simple structure.

In the cooling apparatus may further include a control means.

The control means controls a movement of the opening member by the movement mechanism so that the second state is periodically switched to the first state.

In this embodiment, the second state (cooling mode) is periodically switched to the first state (dust removal mode), with the result that the dust can be removed from the heat sink before the dust that adheres to the heat sink and accumulates thereon causes clogging of radiation fins.

In the cooling apparatus, the blower mechanism may further include a blade member that generates airflow flown out from the blower opening by rotation thereof.

In this case, the control means may control the movement of the opening member so that the second state is switched to the first state when one of start and stop of the rotation of the blade member is performed.

With this structure, the dust can be removed from the heat sink before the dust that adheres to and accumulates on the heat sink causes clogging of the radiation fins.

In the case where the blade member is provided to the cooling apparatus, the cooling apparatus may further includes a rotation counting means and a rotation count judging means.

The rotation counting means counts a number of rotations of the blade member.

The rotation count judging means judges whether the number of rotations counted reaches a specified count.

In this case, the control means may control the movement of the opening member so that the second state is switched to the first state when the number of rotations reaches the specified count.

With this structure, the dust can be removed from the heat sink before the dust that adheres to and accumulates on the heat sink causes clogging of the radiation fins.

The cooling apparatus may further include a time counting means and a time judging means.

The time counting means counts a time period that elapses from when the first state is switched to the second state.

The time judging means judges whether the time period counted reaches a specified time period.

In this case, the control means may control the movement of the opening member so that the second state is switched to the first state when the time period reaches the specified time period.

With this structure, the dust can be removed from the heat sink before the dust that adheres to and accumulates on the heat sink causes clogging of the radiation fins.

According to another embodiment of the present invention, there is provided a cooling apparatus including a heat sink, a blower mechanism, a rotary member, and a rotary mechanism.

The blower mechanism has a blower opening that has a predetermined area and is opposed to the heat sink.

The rotary member includes a shield portion and is rotatable and disposed between the heat sink and the blower opening.

The shield portion limits the area of the blower opening.

The rotary mechanism rotates the rotary member to perform switching between a first state and a second state. The first state is a state in which the area of the blower opening is limited by the shield portion, and the second state is a state in which the area of the blower opening is free of being limited by the shield portion.

In this embodiment, in the first state, the area of the blower opening is limited by the shield portion of the rotary member. Accordingly, the area of the blower opening can be temporarily made smaller. As a result, the flow rate of the airflow flown out from the blower opening can be increased, which can remove the dust that adheres to and accumulates on the heat sink (dust removal mode).

On the other hand, in the second state, the area of the blower opening is not limited by the shield portion of the rotary member. Accordingly, in the second state, the airflow is directed to the heat sink from the entire blower opening, thereby cooling the heat sink (cooling mode).

Further, in this embodiment, the switching between the first state (dust removal mode) and the second mode (cooling mode) can be automatically performed by the rotary mechanism. Thus, it is possible to eliminate the troublesome task of detaching the heat sink from the electronic apparatus such as the PC and washing it.

In the cooling apparatus, the blower opening may have a longitudinal direction.

In this case, the rotary member may be rotatable about a shaft extended along the longitudinal direction.

In this embodiment, because the rotary member is rotated about the shaft extended along the longitudinal direction of the blower opening, a distance between the blower opening and the heat sink can be reduced as compared to a case where the rotary member is rotated about a shaft extended along a short-side direction of the blower opening. Thus, the cooling apparatus can be downsized.

In the cooling apparatus, the rotary member may include a first rotary member and a second rotary member that are disposed while the blower opening being disposed therebetween.

With this structure, the distance between the blower opening and the heat sink can b reduced, with the result that the cooling apparatus can be downsized.

According to another embodiment of the present invention, there is provided an electronic apparatus including a heat generation source and a cooling apparatus.

The cooling apparatus includes a heat sink, a blower mechanism, an opening member, and a movement mechanism.

The heat sink radiates heat transferred from the heat generation source.

The blower mechanism has a blower opening that has a predetermined area and is opposed to the heat sink.

The opening member has a first opening that has an area smaller than the area of the blower opening.

The movement mechanism moves the opening member to perform switching between a first state and a second state. The first state is a state in which the first opening is disposed between the blower opening and the heat sink, and the second state is a state in which the first opening is removed from between the blower opening and the heat sink.

According to another embodiment of the present invention, there is provided an electronic apparatus including a heat generation source and a cooling apparatus.

The cooling apparatus including a heat sink, a blower mechanism, a rotary member, and a rotary mechanism.

The heat sink radiates heat transferred from the heat generation source.

The blower mechanism has a blower opening that has a predetermined area and is opposed to the heat sink.

The rotary member includes a shield portion and is rotatable and disposed between the heat sink and the blower opening.

The shield portion limits the area of the blower opening.

The rotary mechanism rotates the rotary member to perform switching between a first state and a second state. The first state is a state in which the area of the blower opening is limited by the shield portion, and the second state is a state in which the area of the blower opening is free of being limited by the shield portion.

According to another embodiment of the present invention, there is provided a blower apparatus including a blower mechanism, an opening member, and a movement mechanism.

The blower mechanism has a blower opening that has a predetermined area.

The opening member has a first opening that has an area smaller than the area of the blower opening.

The movement mechanism moves the opening member to perform switching between a first state and a second state. The first state is a state in which the first opening is disposed in front of the blower opening, and the second state is a state in which the first opening is removed from the front of the blower opening.

According to another embodiment of the present invention, there is provided a blower apparatus including a blower mechanism, a rotary member, and a rotary mechanism.

The blower mechanism has a blower opening that has a predetermined area.

The rotary member including a shield portion and is rotatable and disposed in front of the blower opening.

The shield portion limits the area of the blower opening.

The rotary mechanism rotates the rotary member to perform switching between a first state and a second state. The first state is a state in which the area of the blower opening is limited by the shield portion, and the second state is a state in which the area of the blower opening is free of being limited by the shield portion.

According to another embodiment of the present invention, there is provided a cooling apparatus including a heat sink, a blade member, a flow path member, a limiting member, and a drive mechanism.

The heat sink has a surface to which airflow is directed.

The blade member generates the airflow to the surface.

The flow path member forms a flow path through which the airflow is guided from the blade member to the heat sink.

The limiting member is capable of limiting the flow path.

The drive mechanism drives the limiting member so that switching between a first state and a second state is performed. The first state is a state in which the flow path is free of being limited by the limiting member, and the second state is a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface.

In this embodiment, in the first state, the limiting member does not limit the flow path, and the flow path is released. In this case, the airflow generated by the blade member is directed to the heat sink, thereby cooling the heat sink (cooling mode).

On the other hand, in the second state, the limiting member limits the flow path. In this case, the airflow that passes through the flow path is changed, thereby generating the vortex so as to be contacted with the heat sink. The vortex blows away the dust that adheres to and accumulates on the heat sink, with the result that the dust can be removed therefrom (dust removal mode).

In addition, in this embodiment, it is possible to automatically switch the first state (cooling mode) and the second state (dust removal mode) by using the drive mechanism. Accordingly, the troublesome task of detaching the heat sink from the electronic apparatus such as the PC and washing it can be eliminated.

The cooling apparatus may further include a control means for controlling the drive mechanism so that the first state is periodically switched to the second state.

In this embodiment, the first state (cooling mode) is periodically switched to the second state (dust removal mode), with the result that the dust can be removed from the heat sink before the dust that adheres to the heat sink accumulates thereon and causes clogging of the radiation fins.

In the cooling apparatus, the blade member may generate the airflow by rotation thereof

In this case, the control means controls the drive mechanism so that the first state is switched to the second state when the rotation of the blade member is started.

With this structure, it is possible to remove the dust from the heat sink before the dust that adheres to the heat sink accumulates thereon and causes clogging of the radiation fins.

In the cooling apparatus, in the case where the blade member generates the airflow by rotation thereof, the control means may control the drive mechanism so that the first state is switched to the second state when the rotation of the blade member is stopped.

With this structure, it is possible to remove the dust from the heat sink before the dust that adheres to the heat sink accumulates thereon and causes clogging of the radiation fins.

In the case where the blade member generates the airflow by rotation thereof in the cooling apparatus, the cooling apparatus may further includes a rotation counting means and a rotation count judging means.

The rotation counting means counts a number of rotations of the blade member.

The rotation count judging means judges whether the number of rotations counted reaches a specified count.

In this case, the control means may control the drive mechanism so that the first state is switched to the second state when the number of rotations reaches the specified count.

With this structure, it is possible to remove the dust from the heat sink before the dust that adheres to the heat sink accumulates thereon and causes clogging of the radiation fins.

The cooling apparatus may further include a time counting means and a time judging means.

The time counting means counts a time period that elapses from when the second state is switched to the first state.

The time judging means judges whether the time period counted reaches a specified time period.

In this case, the control means may control the drive mechanism so that the first state is switched to the second state when the time period reaches the specified time period.

With this structure, it is possible to remove the dust from the heat sink before the dust that adheres to the heat sink accumulates thereon and causes clogging of the radiation fins.

According to another embodiment of the present invention, there is provided an electronic apparatus including a heat generation source and a cooling apparatus.

The cooling apparatus includes a heat sink, a blade member, a flow path member, a limiting member, and a drive mechanism.

The heat sink has a surface to which airflow is directed and radiates heat transferred from the heat generation source.

The blade member generates the airflow to the surface.

The flow path member forms a flow path through which the airflow is guided from the blade member to the heat sink.

The limiting member is capable of limiting the flow path.

The drive mechanism drives the limiting member so that switching between a first state and a second state is performed. The first state is a state in which the flow path is free of being limited by the limiting member, and the second state is a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface.

According to another embodiment, there is provided a blower apparatus including a blade member, a flow path member, a limiting member, and a drive mechanism.

The blade member generates airflow to a surface of a heat sink having the surface to which the airflow is directed.

The flow path member forms a flow path through which the airflow is guided from the blade member to the heat sink.

The limiting member is capable of limiting the flow path.

The drive mechanism drives the limiting member so that switching between a first state and a second state is performed. The first state is a state in which the flow path is free of being limited by the limiting member, and the second state is a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface.

As described above, according to the embodiments of the present invention, it is possible to provide the blower apparatus capable of automatically removing the dust that adheres to the heat sink, the cooling apparatus including the blower apparatus and the heat sink, and the electronic apparatus equipped with the cooling apparatus.

These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of best mode embodiments thereof, as illustrated in the accompanying drawings.

Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a perspective view showing an electronic apparatus equipped with a cooling apparatus according to a first embodiment;

FIG. 2 is a perspective view of the cooling apparatus according to the first embodiment;

FIG. 3 is a top plan view of the cooling apparatus according to the first embodiment;

FIG. 4 is a diagram showing a position of an opening member in a case where the opening member is not driven;

FIG. 5 are diagrams each showing a relative position of a blower opening and the opening member (adjustment opening) in a case where the opening member is driven;

FIG. 6 are diagrams each showing a relationship between coordinates of positions in the blower opening and flow rates of airflow flown out from the blower opening in a cooling mode and a dust removal mode;

FIG. 7 is a perspective view of a cooling apparatus according to a second embodiment;

FIG. 8 is a development view showing the opening member;

FIG. 9 are diagrams for explaining an operation of the cooling apparatus according to the second embodiment when the blower opening and the opening member are viewed from the front of the blower opening;

FIG. 10 is a perspective view of a cooling apparatus according to a third embodiment;

FIG. 11 is a development view showing the opening member;

FIG. 12 are diagrams for explaining an operation of the cooling apparatus according to the third embodiment when the blower opening and the opening member are viewed from the front of the blower opening;

FIG. 13 is an exploded perspective view of a cooling apparatus according to a fourth embodiment;

FIG. 14 is a perspective view of the cooling apparatus 400 according to the fourth embodiment;

FIG. 15 are diagrams for explaining an operation of the cooling apparatus according to the fourth embodiment when the cooling apparatus is viewed from the side;

FIG. 16 are diagrams each showing a relationship between coordinates of positions in the blower opening and flow rates of airflow flown out from the blower opening in the cooling mode and the dust removal mode;

FIG. 17 are diagrams for explaining an operation of a cooling apparatus according to a modified example when the cooling apparatus is viewed from the side;

FIG. 18 is a flowchart showing an operation in a first mode regarding a mode switching timing;

FIG. 19 is a flowchart showing an operation in a second mode regarding a mode switching timing;

FIG. 20 is a flowchart showing an operation in a third mode regarding a mode switching timing;

FIG. 21 is a flowchart showing an operation in a fourth mode regarding a mode switching timing;

FIG. 22 is a perspective view showing an electronic apparatus equipped with a cooling apparatus according to a fifth embodiment;

FIG. 23 is a perspective view showing the cooling apparatus according to the fifth embodiment;

FIG. 24 is an exploded perspective view showing the cooling apparatus according to the fifth embodiment;

FIG. 25 is a side cross-sectional view showing the cooling apparatus according to the fifth embodiment;

FIG. 26 are schematic views for explaining operations of the cooling apparatus according to the fifth embodiment;

FIG. 27 is a view showing a state in which dust is adhered to a heat sink;

FIG. 28 is an enlarged view showing the heat sink to which the dust is adhered;

FIG. 29 are views each showing a relationship between a generation area of a secondary vortex and various parameters;

FIG. 30 is a diagram for explaining a relationship between an expansion factor of flow path and a size of the secondary vortex, and showing a schematic model of enlarged airflow;

FIG. 31 is a graph showing a relationship between a ratio xR/b0 of a re-adhesion distance xR to a slit gap b0 and an expansion ratio D/b0;

FIG. 32 is a view showing a test apparatus used for evaluating dust removal performance;

FIG. 33 is a graph showing a comparison among flow path resistances of the heat sink prior to a test, in a case where the dust removal performance is provided, and in a case where the dust removal performance is not provided;

FIG. 34 is a flowchart showing an operation in a fifth mode regarding a mode switching timing;

FIG. 35 is a flowchart showing an operation in a sixth mode regarding a mode switching timing;

FIG. 36 is a flowchart showing an operation in a seventh mode regarding a mode switching timing; and

FIG. 37 is a flowchart showing an operation in an eighth mode regarding a mode switching timing.

DETAILED DESCRIPTION

The present application will be described with reference to the drawings according to an embodiment.

First Embodiment

FIG. 1 is a perspective view showing an electronic apparatus equipped with a cooling apparatus according to this embodiment. It should be noted that in the description of this embodiment, a laptop PC is used as an example of the electronic apparatus equipped with the cooling apparatus.

As shown in FIG. 1, a laptop PC 101 includes an upper casing 91, a lower casing 92, and a hinge portion 93 that rotatably connects the upper casing 91 and the lower casing 92 with each other. The upper casing 91 includes a display portion 94 such as a liquid crystal display and an EL (electro-luminescence) display.

The lower casing 92 includes a plurality of input keys 95 and a touch pad 96 on an upper surface 92 a and includes an outlet 97 on a side surface 92 b. Further, the lower casing 92 includes an intake (not shown) on a bottom surface 93 c, for example.

A cooling apparatus 100 is disposed so as to be close to the outlet 97 in the lower casing 92.

FIG. 2 is a perspective view of the cooling apparatus according to this embodiment, and FIG. 3 is a top plan view of the cooling apparatus.

As shown in FIGS. 2 and 3, the cooling apparatus 100 according to this embodiment of the present invention includes a centrifugal blower mechanism 10, a heat sink 20, and an opening member 30 that is movable between a blower opening 4 and the heat sink 20. The cooling apparatus 100 further includes a drive mechanism 40 that drives the opening member 30. It should be noted that in FIG. 1, the blower mechanism 10, the opening member 30, and the heat sink 20 are more separate than they really are, for ease of explanation of the structure of the cooling apparatus 100.

The blower mechanism 10 is a centrifugal blower mechanism, and includes a fan case 1, a centrifugal blade member 2 that is rotatable in the fan case 1, and a fan drive motor 5 that rotates and drives the blade member 2.

The blade member 2 is capable of rotating about a shaft extended in a z-axis direction and is subjected to counterclockwise rotary drive by the rotation of the fan drive motor 5. The rotation of the blade member 2 generates airflow to the heat sink 20.

The fan case 1 includes an upper intake 3 on an upper surface 1 a of the fan case 1 and a lower intake (not shown) on a bottom surface 1 c thereof. The upper intake 3 and the lower intake are provided in the vicinity of the center of the upper surface 1 a and the bottom surface 1 c of the fan case 1, respectively. Through the upper intake 3 and the lower intake, air around the blower mechanism 10 is taken in the fan case 1.

The fan case 1 further includes a blower opening (outlet) 4 on a side peripheral surface 1 b. The blower opening 4 has a rectangular shape that is long in one direction (x-axis direction). Through the blower opening 4, airflow is delivered to the heat sink 20. In the following description, a length (x-axis direction) of the blower opening 4 is represented by L1 and a height (z-axis direction) thereof is represented by H1.

The heat sink 20 has a rectangular parallelepiped shape that is long in one direction (x-axis direction), and includes a plurality of radiation fins 21 and a support plate 22 that supports the radiation fins 21 from below. The plurality of radiation fins 21 are aligned at predetermined intervals in a longitudinal direction (x-axis direction) of the heat sink 20. Through the gaps of the radiation fins 21, airflow generated by the blower mechanism passes. The heat sink 20 is made of a metal such as aluminum and copper, for example. However, the material of the heat sink 20 is not particularly limited.

The heat sink 20 is thermally connected to a heat source such as a CPU provided in the lower casing 92 of the laptop PC 101, for example.

The heat sink 20 is disposed so as to face the blower opening 4 and be close to the blower opening 4 (see, FIG. 3). A length L2 and a height H2 of the heat sink 20 are almost the same as the length L1 and the height H1 of the blower opening 4, respectively.

The opening member 30 has a rectangular thin-plate shape that is long in one direction (x-axis direction). For example, the opening member 30 is made of a metal, a resin, or the like, but the material thereof is not limited to those. A height H3 of the opening member 30 is set to be almost the same as or slightly larger than the height H1 of the blower opening 4, and a length L3 of the opening member 30 is set to be about twice the length L1 of the blower opening 4.

In the vicinity of the center of the opening member 30, an opening 31 (hereinafter, referred to as adjustment opening 31) whose size is smaller than the area of the blower opening is formed. Further, the opening member 30 is provided with a plurality of rack gears 32 in the longitudinal direction (x-axis direction) of the opening member 30.

The adjustment opening 31 has a rectangular shape, for example, but the shape is not limited to this. The adjustment opening 31 may have a circular, oval, or polygonal shape, for example.

The drive mechanism 40 includes a pinion 41 and a motor 42. The pinion 41 is engaged with the rack gears of the opening member 30. The motor 42 rotates and drives the pinion 41. The motor 42 may be a typical motor, but when a stepper motor is used for the motor 42, the movement of the opening member 30 can be positively controlled. The same holds true for motors used in the following embodiments.

The opening member 30 is movable between the blower opening 4 and the heat sink 20 in the x-axis direction by being driven by the drive mechanism 40. It is to be noted that the movement of the opening member 30 may be controlled so that the opening member 30 moves in the x-axis direction by a guide (not shown).

(Description of Operation)

Next, a description will be given on an operation of the cooling apparatus 100. FIG. 4 is a diagram showing a position of the opening member 30 in a case where the opening member 30 is not driven. Meanwhile, FIG. 5 are diagrams each showing a relative position of the blower opening 4 and the opening member 30 (adjustment opening 31) in a case where the opening member 30 is driven. It should be noted that FIG. 5 each show a state when the blower opening 4 and the opening member (adjustment opening 31) are viewed from a front side of the blower opening 4.

As shown in FIG. 4, normally, the opening member 30 is not driven by the drive mechanism 40 and is stopped in a state where the opening member 30 is not located between the blower opening 4 and the heat sink 20.

First, a description will be given on an operation of the cooling apparatus 100 in a case where the opening member 30 is stopped in the state of being not disposed between the blower opening 4 and the heat sink 20.

When the blade member 2 is rotated, air in the lower casing 92 of the laptop PC 101 is taken in the fan case 1 through the upper intake 3 and the lower intake.

The air taken in the fan case 1 is accelerated in a centrifugal direction by the rotation of the blade member, flown out from the blower opening 4, and directed to the heat sink 20. In this case, the blower opening 4 is fully opened. Therefore, the airflow from the blower opening 4 is entirely directed to a surface 20 a (hereinafter, referred to as opposed surface 20 a) of the heat sink 20, which is opposed to the blower opening 4.

From the radiation fins 21, the heat sink 20 radiates heat transferred from the heat generation source such as the CPU provided to the laptop PC 101. Warmed air between the radiation fins 21 is carried by the airflow from the blower opening 4 and forcibly exhausted to the outside of the lower casing 92 through the outlet 97 provided to the lower casing 92. As a result, the heat generation source such as the CPU is cooled.

It should be noted that in this specification, the state where the heat sink 20 is cooled with the blower opening 4 being fully opened is referred to as a cooling mode.

Here, because air in the lower casing 92 taken therein from the upper intake 3 and the lower intake of the blower mechanism 10 contains the dust, airflow delivered from the blower opening 4 also contains the dust. Therefore, when the airflow is directed to the heat sink 20, the dust is also directed to the heat sink 20 and adheres thereto. In particular, the dust easily adheres to and accumulates on the opposed surface 20 a of the heat sink 20, which is opposed to the blower opening 4.

If the cooling mode is maintained for a long time period, the radiation fins 21 are clogged with the dust. As a result, ventilation through the radiation fins is hindered, resulting in reduction in the cooling performance of the cooling apparatus 100.

Next, an operation in a case where the opening member 30 is driven will be described with reference to FIGS. 5A to 5I.

As shown in FIG. 5A, when the rotation of the motor 42 is started and then the rotary drive of the pinion 41 is started, the opening member 30 starts to move leftward. In this case, the rotation movement of the pinion 41 by the rack gears 32 provided to the opening member 30 causes a linear movement of the opening member 30, and thus the opening member 30 is started to move leftward.

It should be noted that timing at which the opening member 30 is driven will be described later in detail.

As shown in FIG. 5B, the opening member 30 goes between the blower opening 4 and the heat sink 20 from an left end portion of the opening member 30.

As shown in FIG. 5C, when the adjustment opening 31 is moved to a position opposed to a right end portion of the blower opening 4 and disposed between the blower opening 4 and the heat sink 20, the airflow is directed to the heat sink 20 through the adjustment opening 31. At this time, an apparent area of the blower opening 4 is reduced by the adjustment opening 31, and therefore a flow rate of the airflow directed to the heat sink is locally increased. As a result, the dust that adheres to and accumulates on the gaps between the radiation fins 21 of the heat sink 20 can be blown away. The dust blown away is discharged to the outside of the laptop PC 101 through the outlet 97 provided to the lower casing 92 of the laptop PC 101.

It should be noted that in this specification, the state where the adjustment opening 31 is located between the blower opening 4 and the heat sink 20 and strong airflow is directed to the heat sink 20 through the adjustment opening is referred to as a dust removal mode.

As shown in FIGS. 5D and 5E, even after the adjustment opening 31 reaches the right end portion of the blower opening 4, the leftward movement of the opening member 30 is continued until the adjustment opening 31 gets to the position opposed to a left end portion of the blower opening.

At this time, the adjustment opening 31 is moved from the right end portion of the blower opening 4 to the left end portion of the blower opening 4 between the blower opening 4 and the heat sink 20. In this case, the adjustment opening 31 moves along the blower opening 4 while directing the strong airflow to the heat sink 20. Therefore, the entire opposed surface 20 a of the heat sink 20 can receive the strong airflow. As a result, the dust that adheres to the heat sink 20 can be removed from the entire heat sink 20.

When the adjustment opening 31 gets to the left end portion of the blower opening 4 (see, FIG. 5E), a reverse rotation of the motor 42 is started, thereby starting a reverse rotation of the pinion, with the result that the opening member 30 is started to move rightward.

As shown in FIGS. 5F and 5G, the adjustment opening 31 is moved from the left end portion of the blower opening 4 to the right end portion thereof between the blower opening 4 and the heat sink. That is, the adjustment opening 31 is moved in the reverse direction to the direction in the above-described case, i.e., from left end portion of the blower opening 4 to the right end portion thereof, and the strong airflow is directed to the entire heat sink 20, thereby entirely removing the dust that adheres to the heat sink 20.

As shown in FIG. 5H, even after the adjustment opening 31 reaches the right end portion of the blower opening 4, the opening member 30 is continued to move in the positive x direction.

As shown in FIG. 5I, when the opening member 30 is moved to a position at which the opening member 30 does not face the front of the blower opening, the rotary drive of the pinion 41 by the motor 42 is stopped, thereby stopping the movement of the opening member 30. When the opening member 30 is moved to the position shown in FIG. 5I, the airflow is directed to the heat sink 20 from the entire blower opening 4, thereby cooling the heat sink 20 again (cooling mode).

In the description with reference to FIGS. 5A to 5I, the case where the opening member 30 is reciprocated between the blower opening 4 and the heat sink 20 once is shown. But, the number of the reciprocating movements is not limited to one, and the opening member 30 may be reciprocated two or more times. With this operation, the dust can be positively removed from the heat sink 20.

As described above, the cooling apparatus 100 according to this embodiment can remove the dust from the heat sink 20 by moving the opening member 30, and thus can prevent the radiation fins 21 from being clogged with the dust and prevent the cooling performance of the cooling apparatus 100 from deteriorating.

In addition, the cooling apparatus 100 according to this embodiment can automatically remove the dust that adheres to the heat sink 20, and thus can eliminate the troublesome task of detaching the heat sink 20 from the laptop PC 101 and washing the heat sink 20.

Further, in this embodiment, the dust can be removed from the heat sink 20 by directing the strong airflow thereto without increasing the rotation speed of the blade member 2 of the blower mechanism 10. Thus, an excessive increase of power consumption of the cooling apparatus 100 can be suppressed. In addition, even when the power of the fan drive motor 5 that rotates the blade member 2 is small and the strong airflow is difficult to be generated, the dust can be removed from the heat sink 20 by directing the strong airflow to the heat sink 20.

Next, a dust removal performance of the cooling apparatus 100 according to this embodiment will be described in more detail.

In order to evaluate the dust removal performance, the inventors of the present invention measured the flow rate of the airflow directed from the blower opening 4 with the blower opening 4 being fully opened (in the cooling mode), and measured the flow rate of the airflow in the case where the airflow is directed through the adjustment opening 31 (in the dust removal mode).

For evaluation of the dust removal performance, the flow rate of the airflow in the case where the blower opening 4 was fully opened (in the cooling mode) and the flow rate of the airflow in the case where the apparent area of the blower opening 4 was made small by the adjustment opening 31 (in the dust removal mode) were compared.

The length L1 and the height H1 of the airflow opening 4 used for the evaluation of the dust removal performance were set to 70 mm and 10 mm, respectively, and the width and the height of the adjustment opening 31 were set to 10 mm and 10 mm, respectively. Further, the length L2, the height H2, and the depth of the heat sink 20 were set to 70 mm, 10 mm, and 18 mm, respectively, and the intervals between the radiation fins 21 were set to 1 mm.

For the measurement of the flow rate of the airflow, Climomaster Model 6542 (registered trademark) (hereinafter, simply referred to as anemometer) manufactured by Kanomax Japan, Inc. was used.

In the state where the blower opening 4 was fully opened, the flow rate of the airflow in the cooling mode was measured at distances of 10 mm, 15 mm, 20 mm, 25 mm, . . . 60 mm from the left end portion of the blower opening 4. Specifically, the flow rate was measured at each of the measurement positions (10, 15, . . . 60) in the blower opening 4 with an end portion of a probe provided to the anemometer being set at the center of the blower opening 4 at each of the measurement positions (10, 15, . . . 60).

Meanwhile, in the dust removal mode, the adjustment opening 31 was opposed to each of the measurement positions (10, 15, . . . 60) in the blower opening 4 and the flow rate was measured at each of the measurement positions (10, 15, . . . 60) with the end portion of the probe of the anemometer being set at the center of the adjustment opening 31.

FIG. 6A is a table showing a relationship between coordinates of the positions in the blower opening 4 and the flow rates of the airflow directed from the blower opening in the cooling mode and the dust removal mode.

FIG. 6B is a graph of the relationship shown in FIG. 6A. In FIG. 6B, a horizontal axis indicates the coordinates of the positions (mm) in the blower opening 4 in the x-axis direction, and a vertical axis indicates the flow rates (m/s) of the airflows of directed from the blower opening 4.

In addition, in FIG. 6B, the graph indicated by the dashed line and the square dots shows the relationship between the positions in the blower opening 4 and the flow rates in the cooling mode. On the other hand, in FIG. 6B, the graph indicated by the solid line and the rhomboid dots shows the relationship between the positions in the blower opening 4 and the flow rates in the dust removal mode.

As shown in FIGS. 6A and 6B, the flow rates of the airflows that passed through the adjustment opening 31 were significantly increased as compared to the case where the blower opening 4 was fully opened.

As a result of the measurement conducted by the inventors of the present invention, it was found that when the flow rate of the airflow was approximately 10 m/s, the dust that clogged the radiation fins 21 was easily removed from between the radiation fins. As shown in FIGS. 6A and 6B, in the dust removal mode, the flow rate exceeded 10 m/s at each of the position coordinates (10, 15, . . . 60), and it was verified that the dust adhered to the radiation fins was desirably removed.

In FIGS. 6A and 6B, particularly characteristically, as the flow rate becomes lower in the case where the blower opening 4 is fully opened, the flow rate of the airflow that passes through the adjustment opening 31 becomes higher. This reveals that as the position is more likely to get the dust because of the low flow rate in the fully opened state of the blower opening, the dust can be removed more strongly.

As described above, the fact that the flow rate of the airflow that passes through the adjustment opening 31 becomes higher as the flow rate becomes lower in the fully opened state of the blower opening 4 is attributed to the fact that a pressure is more increased as the flow rate becomes lower in the state where the blower opening 4 is fully opened. Therefore, when the pressurized airflow passes through the adjustment opening 31, the flow rate becomes higher.

Second Embodiment

Next, a second embodiment of the present invention will be described. It should be noted that in the description of the second and subsequent embodiments, the members having the same structures and functions as the first embodiment are denoted by the same reference numerals or symbols, and their descriptions will be omitted or simplified.

FIG. 7 is a perspective view showing a cooling apparatus 200 according to the second embodiment. It should be noted that a gap between the blower opening 4 of the blower mechanism 10 and the heat sink 20 is more separate than it really is, for ease of explanation of the structure of the cooling apparatus 200.

As shown in FIG. 7, the cooling apparatus 200 according to the second embodiment includes the blower mechanism 10 having the blower opening 4 and the heat sink 20 disposed at a position opposed to the blower opening 4. In addition, the cooling apparatus 200 further includes an opening member 50 having flexibility and first and second storage portions 60 and 70 that are capable of rolling up and storing the opening member 50 and rolling out the opening member 50. The blower opening 4 and the heat sink 20 are close to each other with the opening member 50 being disposed therebetween.

The first storage portion 60 is disposed at a position close to a left edge portion 4 c of the blower opening 4, and the second storage portion 70 is disposed at a position close to a right edge portion 4 d of the blower opening. In other words, the first storage portion 60 and the second storage portion 70 are disposed so as to sandwich the blower opening 4 in a longitudinal direction (x-axis direction) of the blower opening 4.

The first storage portion 60 disposed at the left side of the blower opening 4 includes a first drive mechanism 64 that drives the opening member 50 and a first case 61 that stores the opening member 50 that is rolled up. The first drive mechanism 64 includes a first spindle 62 that is rotatable about a shaft extended in the z-axis direction and a first motor 63 that rotates and drives the first spindle 62. The first spindle 62 is connected to a left end portion of the opening member 50. The first case 61 has, for example, a cylindrical shape, but the shape thereof is not limited to this.

Similarly, the second storage portion 70 disposed at the right side of the blower opening 4 includes a second drive mechanism 74 and a second case 71 that stores the opening member 50 that is rolled up. The second drive mechanism 74 has a second spindle 72 and a second motor 73. The second spindle 72 is connected to a right end portion of the opening member 50.

FIG. 8 is a development view showing the opening member 50.

As shown in FIG. 8, the opening member 50 is long in one direction (x-axis direction). The opening member 50 is a band-like shape, and is formed of paper, cloth, or a resin having flexibility such as a film, for example. But, the material of the opening member 50 is not limited to those, and any material may be used as long as it is flexible and capable of being rolled up.

The opening member 50 includes an adjustment opening 51 having an area smaller than that of the blower opening 4. The opening member 50 further includes first and second openings 52 and 53 (hereinafter, referred to as full opening) each having an area that is almost the same as the blower opening 4. That is, the opening member 50 has the three openings, specifically, the adjustment opening 51 formed at the center of the opening member 50, the first full opening 52 formed at the left side of the adjustment opening 51, and the second full opening 53 formed at the right side of the adjustment opening 51.

The first full opening 52 disposed at the left side of the adjustment opening 51 has a height h1 and a width w1 which are almost the same as the height H1 and the length L1 of the blower opening 4, respectively. Similarly, the second full opening 53 disposed at the right side of the adjustment opening 51 has a height h2 and a width w2 which are almost the same as the height H1 and the length L1 of the blower opening 4, respectively.

A distance d1 between a right end portion of the first full opening 52 and a left end portion of the adjustment opening 51 is preset to be almost the same as the length L1 of the blower opening 4. Similarly, a distance d2 between a left end portion of the second full opening 53 and a right end portion of the adjustment opening 51 is preset to be almost the same as the length L1 of the blower opening 4.

The opening member 50 can be moved along the blower opening 4 by being driven by the first drive mechanism 64 and the second drive mechanism 74.

(Description of Operation)

Next, a description will be given on an operation of the cooling apparatus 200 according to the second embodiment. FIGS. 9A to 9G are diagrams for explaining the operation when the blower opening 4 and the opening member 50 are viewed from the front of the blower opening 4.

As shown in FIG. 9A, the opening member 50 is stopped at a position where the first full opening 52 is opposed to the blower opening 4. In this case, the blower opening 4 is fully opened, and the airflow delivered from the blower opening 4 is directed to the entire opposed surface 20 a of the heat sink 20 through the first full opening 52, thereby cooling the heat sink (cooling mode).

When the drive of the first motor 61 is started, a rotary drive of the first spindle 62 is started, and then a roll-up operation of the opening member 50 is started by the first spindle 62. When the first spindle 62 is rotated and driven, the second spindle 72 is rotated in conjunction therewith, thereby rolling out the opening member 50 rolled up. In this case, typically, the second motor 73 is not driven, but may be driven to forcibly roll out the opening member 50.

As shown in FIG. 9B, when the first spindle 62 starts to roll up the opening member 50, the opening member 50 is started to move leftward, and along with this movement, the first full opening 52 is started to move leftward.

As shown in FIG. 9C, when the first full opening 52 is moved to a position outside the front of the blower opening 4, the adjustment opening 51 put out by the second spindle 72 is moved to a position where the adjustment opening 51 is opposed to the right end portion of the blower opening 4. When the adjustment opening 51 is put out to the front of the blower opening 4 and disposed between the blower opening 4 and the heat sink 20, the strong airflow is directed to the heat sink 20 (dust removal mode). As a result, the dust that adheres to and accumulates on the radiation fins 21 can be blown away.

As shown in FIG. 9D, the adjustment opening 51 is moved along the blower opening 4 while directing the strong airflow to the heat sink 20. Thus, the dust that adheres to the heat sink 20 can be removed from the entire heat sink 20.

As shown in FIG. 9E, when the adjustment opening 51 is moved to the outside of the front of the blower opening 4, the second full opening 53 gets to the front of the blower opening 4 from the right side of the blower opening 4.

As shown in FIG. 9F, the second full opening 53 is moved leftward along the blower opening.

As shown in FIG. 9G, when the second full opening 53 is moved to the position opposed to the blower opening 4, the drive of the first motor is stopped, and the movement of the opening member 50 is stopped. When the movement of the opening member 50 is stopped, the airflow delivered from the blower opening 4 is directed to the entire opposed surface 20 a of the heat sink 20 through the second full opening 53, thereby cooling the heat sink (cooling mode).

In a case where the state in which the second full opening 53 is opposed to the blower opening 4 is switched to the dust removal mode by moving the opening member 50, the second spindle 72 is rotated and driven, and the opening member 50 is moved rightward. It should be noted that the operation in this case is the same as the operation of moving the opening member 50 leftward, so the detailed description thereof will be omitted.

In the description with reference to FIGS. 9A to 9G, the case where the opening member 50 is moved in one direction is shown. However, the movement of the opening member 50 is not limited to this, and the opening member 50 may be reciprocated. Further, the opening member may of course be reciprocated two or more times.

Further, in the description of the second embodiment, the number of the adjustment opening 51 is set to one but is not limited to this. The opening member 50 may include two or more adjustment openings 51. In addition, the opening member 50 may include two or more full openings. That is, in the opening member 50, the numbers of adjustment openings and full openings and the distance between the adjustment opening and the full opening may be changed as appropriate without departing from the gist of the present invention.

In the second embodiment, the first storage portion 60 and the second storage portion 70 can roll up the opening member 50 to store it, with the result that a space in which the opening member 50 is disposed can be made small. With this structure, the cooling apparatus 200 can be downsized. It should be noted that the other effects are the same as the first embodiment and their description will be omitted.

Third Embodiment

Next, a cooling apparatus according to a third embodiment of the present invention will be described.

FIG. 10 is a perspective view showing a cooling apparatus 300 according to the third embodiment.

As shown in FIG. 10, the cooling apparatus 300 according to the third embodiment includes the blower mechanism 10 having the blower opening 4, the heat sink 20 disposed at the position opposed to the blower opening 4, and an annular opening member 80 provided so as to surround the blower mechanism 10. The cooling apparatus 300 further includes first to fifth spindles 85 to 89 that are provided around the blower mechanism 10.

The first to fifth spindles 85 to 89 support the opening member 80 so as to rotate the opening member 80 around the blower mechanism 10. The first spindle 85 has a cylindrical shape whose radius is larger than those of the second to fifth spindles 86 to 89, and is electrically connected to a motor 84. The first spindle 85 and the motor 84 constitute a drive mechanism 90 that drives the opening member 80.

FIG. 11 is a development view showing the opening member 80.

As shown in FIG. 11, the opening member 80 has three openings, that is, adjustment openings 81 and 82 and a full opening 83. The adjustment openings 81 and 82 each have an area smaller than that of the blower opening 4, and the full opening 83 has an area that is almost the same as the blower opening 4. The opening member 80 is a band-like annular member, and is made of paper, cloth, or a resin having flexibility such as a film, for example. But, the opening member 80 may be made of any material as long as it is flexible and capable of being annularly rotated.

The opening member 80 has a length L4 that is almost the same as a length of the side peripheral surface 1 b of the blower mechanism 10. The full opening 83 has a height h1 and a width w1 that are almost the same as the height H1 and the length L1 of the blower opening 4, respectively. A distance d1 between a right end portion of the full opening 83 and a left end portion of the first adjustment opening 81 and a distance d2 between a right end portion of the first adjustment opening 81 and a left end portion of the second adjustment opening 82 are set to be almost the same as the length L1 of the blower opening 4. In addition, a distance d3 between a right end portion of the second adjustment opening 82 and a left end portion of the full opening 83 is also set to be almost the same as the length L1 of the blower opening 4.

(Description of Operation)

Next, an operation of the cooling apparatus 300 according to the third embodiment of the present invention will be described. FIGS. 12A to 12I are diagrams for explaining the operation, when the blower opening 4 and the opening member 80 are viewed from the front of the blower opening 4.

As shown in FIG. 12A, in the cooling mode, the full opening 83 is stopped at a position opposed to the blower opening 4. The airflow flown out from the blower opening 4 is directed to the entire opposed surface 20 a of the heat sink 20 through the full opening 83.

When the drive of the motor 84 is started, the rotary drive of the first spindle 85 is started, and then the opening member 80 is rotated clockwise around the blower mechanism 10. As shown in FIG. 12B, the clockwise rotation is started, the leftward movement of the opening member 80 is started, and along with this movement, the leftward movement of the full opening 83 is started.

As shown in FIG. 12C, when the full opening 83 is moved to the outside of the front of the blower opening 4, the first adjustment opening 81 is moved to a position opposed to the right end portion of the blower opening 4. When the first adjustment opening 81 is moved to the front of the blower opening 4 and disposed between the blower opening 4 and the heat sink 20, the strong airflow is directed to the heat sink 20 (dust removal mode).

As shown in FIG. 12D, the first adjustment opening 81 is moved along the blower opening 4 while directing the strong airflow to the heat sink 20. As shown in FIG. 12E, when the first adjustment opening 81 is moved to the outside of the front of the blower opening 4, the second adjustment opening 82 is moved to the position opposed to the right end portion of the blower opening 4. As shown in FIG. 12F, the second adjustment opening 82 is moved along the blower opening 4 while directing the strong airflow to the heat sink 20.

As shown in FIG. 12G, when the second adjustment opening 82 is moved to the outside of the front of the blower opening 4, the full opening 83 moved around the blower mechanism 10 gets to the front of the blower opening 4 from the right side thereof.

As shown in FIG. 12H, the full opening 83 is moved leftward along the blower opening 4. Then, as shown in FIG. 12I, when the full opening 83 is moved to the position opposed to the blower opening 4, the drive of the motor 84 is stopped, and the movement of the opening member 80 is stopped. When the movement of the opening member 80 is stopped, the airflow flown out from the blower opening 4 is directed to the entire opposed surface 20 a of the heat sink 20 through the full opening 83, thereby cooling the heat sink (cooling mode).

In the above description, the case where the opening member 80 is rotated clockwise around the blower mechanism 10 is shown. However, the opening member 80 may be rotated counterclockwise. Further, the number of rotations is not limited to one, and the opening member 80 may rotate around the blower mechanism 10 two or more times.

In the description of the third embodiment, the opening member 80 is set to have the two adjustment openings. However, the number of adjustment openings may be one or three or more. In addition, the opening member 80 is set to have the one full opening, but may have two or more full openings. That is, the numbers of adjustment openings and full openings and the distance between the adjustment opening and the full opening may be changed as appropriate depending on the size of the blower mechanism 10 without departing from the gist of the present invention.

In the third embodiment, the opening member 80 can be rotated around the blower opening 4, with the result that the space in which the opening member 80 is disposed can be made small. Thus, the cooling apparatus 300 can be downsized. It should be noted that the other effects are the same as those of the first embodiment, so their descriptions will be omitted.

Fourth Embodiment

Next, the fourth embodiment of the present invention will be described.

FIG. 13 is an exploded perspective view of a cooling apparatus 400 according to the fourth embodiment of the present invention, and FIG. 14 is a perspective view of the cooling apparatus 400 according to the fourth embodiment. It should be noted that, in FIG. 14, a lid portion 154 is omitted to facilitate visualization.

As shown in FIGS. 13 and 14, the cooling apparatus 400 according to the fourth embodiment includes the blower mechanism 10 having the blower opening 4 and the heat sink 20 provided so as to be opposed to the blower opening 4. The cooling apparatus 400 further includes a rotary member 130, a drive mechanism 140, and a support stage 150. The rotary member 130 can be rotated between the blower opening 4 and the heat sink. The drive mechanism 140 drives the rotary member 130. The support stage 150 supports the blower mechanism 10, the heat sink 20, and the rotary member 130.

The rotary member 130 is provided between the blower opening 4 and the heat sink 20. The rotary member 130 has a rectangular thin-plate-like shape that is long in one direction (x-axis direction), and a length L5 of the rotary member is set to be almost the same as the length L1 of the blower opening 4. The rotary member 130 is connected to a spindle 141 at one end portion thereof in a short-side direction and is rotatable about the spindle 141. By the rotation of the rotary member 130, an apparent area of the blower opening 4 can be made small. A material of the rotary member 130 is, for example, a resin or a metal but is not particularly limited.

The drive mechanism 40 includes the spindle 141 that is rotatable about a shaft extended in the x-axis direction and a motor 142 that rotates and drives the spindle 141.

The spindle 141 can rotate at a position opposed to an edge portion 4 a (hereinafter, referred to as lower edge portion 4 a) on a lower side of the blower opening 4. With this structure, the rotary member 130 is caused to rotate about the shaft disposed at the position opposed to the lower edge portion 4 a.

The support stage 150 includes a bottom portion 151, a first side wall portion 152, a second side wall portion 153, and the lid portion 154. The bottom portion 151 supports the rotary member 130 and the heat sink 20 from below. The first side wall portion 152 forms a side wall on the right side of the bottom portion 151, and the second side wall portion 153 forms a side wall on the left side of the bottom portion 151.

The first side wall portion 152 has a through hole 155 that penetrates the first side wall portion 152. Into the through hole 155, the spindle 141 is inserted.

The heat sink 20 is surrounded by the bottom portion 151, the first side wall portion 152, the second side wall portion 153, and the lid portion 154 of the support stage 150 and is fixed to the support stage 150. Further, the blower mechanism 10 is fixed to the support stage 150 in the vicinity of the blower opening 4. The support stage 150 supports the blower mechanism 10, the rotary member 130, and the heat sink 20, and regulates the airflow flown out from the blower opening 4 so that the airflow is directed to the heat sink 20 (y-axis direction).

(Description of Operation)

Next, a description will be given on an operation of the cooling apparatus 400 according to the fourth embodiment. FIGS. 15A and 15B are diagrams for explaining the operation, when the cooling apparatus is viewed from the side.

As shown in FIG. 15A, in the cooling mode, the rotary member 130 is stopped in parallel to a horizontal surface. The airflow flown out from the blower opening 4 is directed to the entire opposed surface 20 a of the heat sink 20.

As shown in FIG. 15B, in the dust removal mode, by performing the rotary drive of the spindle 141 by the motor 142, the rotary member 130 is rotated. In this case, the rotary member 130 is rotated about the shaft extended in a direction along the longitudinal direction of the blower opening 4, which is disposed at a position opposed to the lower edge portion 4 a. The rotary member 130 is stopped for several seconds in the state of being tilted at a 40-degree angle, for example. As a result, the area of the blower opening 4 is temporarily made small, and thus the strong airflow can be directed to the heat sink 20 and the dust can be removed from the heat sink 20. Consequently, the radiation fins 21 can be prevented from being clogged with the dust, and the cooling performance of the cooling apparatus 400 can be prevented from deteriorating. Here, as described above, because the rotary member 130 has the same length as the blower opening 4, the dust can be removed from the entire heat sink 20.

In addition, because the cooling apparatus 400 can automatically remove the dust that adheres to the heat sink 20, the troublesome task of detaching the heat sink 20 from the laptop PC 101 and washing it can be eliminated.

Further, the dust can be removed from the heat sink 20 by directing the strong airflow thereto without increasing the rotation speed of the blade member 2 of the blower mechanism 10. Thus, an excessive increase of power consumption of the cooling apparatus 400 can be suppressed. In addition, even when the power of the fan drive motor 5 that rotates the blade member 2 is small and the strong airflow is difficult to be generated, the dust can be removed from the heat sink 20 by directing the strong airflow to the heat sink 20.

In the description with reference to FIG. 15, the rotary member 130 is stopped with the rotary member 130 being tilted at a 40-degree angle with respect to the horizontal surface. But, the tilt angle with respect to the horizontal surface may be less than or more than 40 degrees. In addition, the time period for which the rotary member is stopped in the state of being tilted is set to several seconds in the above description, but may be set to several minutes.

Next, the dust removal performance of the cooling apparatus 400 according to the fourth embodiment will be described in more detail.

The dust removal performance was evaluated in the same way as the evaluation of the dust removal performance of the cooling apparatus 100 according to the first embodiment. That is, the dust removal performance was evaluated by comparing the flow rate of the airflow at a time when the blower opening 4 was fully opened (in the cooling mode) with the flow rate of the airflow at a time when the apparent area of the blower opening 4 was made smaller by the rotary member 130 (in the dust removal mode).

Conditions of measuring the flow rate of the airflow in the dust removal mode were as follows. The rotary member 130 was stopped with the rotary member 130 being tilted at a 40-degree angle, and the height H1 (10 mm) of the blower opening was apparently reduced to 2 mm. The measurement positions of the airflow were set at upper part of the rotary member 130 in the position coordinates (10, 15, . . . and 60). It should be noted that the other measurement conditions of the airflow were the same as the case described with reference to FIG. 6, so their descriptions will be omitted.

FIG. 16A is a table showing a relationship between the position coordinates of the blower opening 4 and the flow rates of the airflow flown out from the blower opening 4 in the cooling mode and the dust removal mode.

FIG. 16B is a graph showing the relationship shown in FIG. 16A. In FIG. 16B, the graph represented by the dashed line and the square dots shows the relationship between the positions in the blower opening 4 and the flow rates in the cooling mode, and the graph represented by the solid line and the triangular dots shows the relationship between the positions in the blower opening 4 and the flow rates in the dust removal mode.

From FIGS. 16A and 16B, it was found that the flow rate in the case where the area of the blower opening 4 was made smaller by the rotary member 130 is increased as compared to the case where the blower opening 4 was fully opened. In addition, in the case where the rotary member 130 was used, the lower the flow rate in the fully opened state of the blower opening 4, the higher the flow rate of the airflow in the cooling mode, as in the case where the opening member 30 (opening member 50, 80) was used. This reveals that the more likely the position is to get the dust because of the low flow rate in the fully opened state of the blower opening 4, the more strongly the dust can be removed therefrom.

(Modified Examples)

Next, modified examples of the cooling apparatus 400 according to the fourth embodiment will be described. FIGS. 17A and 17B are side views of the cooling apparatuses for explaining the modified examples.

FIG. 17A shows a first modified example. As shown in FIG. 17A, the rotary member 130 of a cooling apparatus 500 according to the first modified example is rotatable about a shaft that is disposed at a position opposed to the center of the blower opening 4 and extended in the longitudinal direction (x-axis direction) of the blower opening 4. The rotary member 130 is rotated upward or downward about the shaft disposed at the position opposed to the center of the blower opening 4. With this structure, the apparent area of the blower opening 4 is made smaller, and the strong airflow is directed to the heat sink 20, with the result that the dust can be removed therefrom.

In the description with reference to FIG. 17A, the rotary member 130 is rotatable about the shaft disposed at the center of the blower opening 4, but is not limited to this. The rotary member 130 may be rotatable about a shaft disposed at a position opposed to an upper edge portion 4 b of the blower opening 4.

FIG. 17B shows a second modified example. As shown in FIG. 17B, a cooling apparatus 600 according to the second modified example is provided with first and second rotary members 131 and 132 so that the blower opening 4 is disposed between the two rotary members 131 and 132. The first rotary member 131 is rotatable about the shaft disposed at the position opposed to the lower edge portion 4 a of the blower opening 4, and the second rotary member 132 is rotatable about a shaft disposed at the position opposed to the upper edge portion 4 b of the blower opening 4. In this way, by providing the two rotary members 131 and 132, the distance d between the blower opening 4 and the heat sink 20 can be reduced. As a result, the cooling apparatus 400 can be downsized.

In the fourth embodiment, the rotary member 130 is rotatable about the shaft extended in the longitudinal direction (x-axis direction) of the blower opening 4. But, the rotary member 130 may instead be rotatable about a shaft extended in the short-side direction (y-axis direction) of the blower opening.

(First Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a first mode regarding timing of switching between the cooling mode and the dust removal mode. Although modes relating to the timing of switching between the cooling mode and the dust removal mode, which will be described in the following, may be applied to any one of the cooling apparatuses 100 to 400 described above, the cooling apparatus 100 is used as an example for convenience of the explanation.

FIG. 18 is a flowchart showing an operation of the first mode regarding the mode switching timing. It should be noted that a CPU is used as a control system of the cooling apparatus 100 in this case.

As shown in FIG. 18, the CPU of the cooling apparatus 100 judges whether a drive start signal of the fan drive motor 5 is input (Step 101). When the drive start signal is not input (No in Step 101), the CPU judges again whether the drive start signal of the fan drive motor 5 is input. In this case, the blower opening 4 is fully opened, and the heat sink 20 is cooled (cooling mode).

For example, when the drive start signal of the fan drive motor 5 is output from the electronic apparatus such as the laptop PC 101, the drive start signal is input to the CPU of the cooling apparatus 100.

When the drive start signal of the fan drive motor 5 is input (Yes in Step 101), the CPU starts to drive the fan drive motor 5 (Step 102). When the drive of the fan drive motor is started, the rotation of the blade member 2 is started, and the airflow is delivered from the blower opening 4.

Next, the CPU starts to drive the motor 42 and controls the movement of the opening member 30 (Step 103). When the opening member 30 is moved, the adjustment opening 31 is moved along the blower opening 4 while directing the strong airflow to the heat sink 20, thereby blowing the dust away from the entire heat sink 20 (see, FIG. 5) (dust removal mode).

After causing the opening member 30 to reciprocate once (or more times) between the blower opening 4 and the heat sink, the CPU stops the drive of the motor 42 and the movement of the opening member 30 (Step 104). When the opening member 30 is stopped, the blower opening 4 is fully opened, and the heat sink 20 is cooled (cooling mode).

When the CPU stops the drive of the motor, the processing returns to Step 101 again, and the subsequent steps are repeated.

By the above processing, it is possible to periodically switch the cooling mode to the dust removal mode. Therefore, it is possible to remove the dust from the heat sink before the dust that adheres to the heat sink accumulates thereon and the clogging of the radiation fins is caused.

(Second Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a second mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 19 is a flowchart showing an operation of the second mode.

As shown in FIG. 19, the CPU judges whether a stop notice signal of the fan drive motor 5 is input (Step 201). When the stop notice signal is not input (No in Step 201), the CPU judges again whether the stop notice signal is input. In this case, the blower opening 4 is fully opened, and the heat sink 20 is cooled (cooling mode).

When the stop notice signal is input (Yes in Step 201), the CPU does not stop the fan drive motor 5 immediately but starts to drive the motor 42 to control the movement of the opening member 30 (Step 202). When the movement of the opening member 30 is started, the adjustment opening 31 is disposed between the blower opening 4 and the heat sink 20, thereby blowing the dust away from the heat sink 20 (dust removal mode).

Next, the CPU stops the drive of the motor 42 (Step 203) and stops the drive of the fan drive motor 5 (Step 204).

By the above processing, it is also possible to periodically remove the dust from the heat sink 20. Thus, the same effect as the first mode can be obtained.

(Third Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a third mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 20 is a flowchart showing an operation of the third mode.

The CPU judges whether the drive of the motor 42 rotated is stopped (Step 301). That is, the CPU judges whether the dust removal mode is switched to the cooling mode and the cooling mode is started. When the drive of the motor 42 rotated is stopped (Yes in Step 301), the CPU sets a timer of a counter to be on and starts counting of count values generated at predetermined intervals. For the counter, a counter dedicated to the cooling apparatus 100 may be used, or a counter equipped to the electronic apparatus such as the laptop PC 101 may be used.

Next, the CPU judges whether the count value reaches a specified value (Step 303). The specified value corresponds to a certain time period, e.g., one week, but is not limited to this.

When the count value reaches the specified value (Yes in Step 303), that is, the certain time period (e.g., one week) elapses from when the cooling mode is started, the CPU judges whether the fan drive motor 5 is driven (Step 304).

In a case where the fan drive motor 5 is driven (Yes in Step 304), the CPU drives the motor 42 and controls the movement of the opening member 30 (Step 305), and thereafter stops the drive of the motor 42 (Step 306) (dust removal mode).

On the other hand, in a case where the fan drive motor 5 is not driven when the count value reaches the specified value (No in Step 304), the CPU judges whether a drive signal of the fan drive motor 5 is input from the electronic apparatus such as the laptop PC 101, for example (Step 307).

When the drive signal of the fan drive motor 5 is input (Yes in Step 307), the CPU drives the fan drive motor 5 (Step 308), and thereafter starts the drive of the motor 42 (Step 305). That is, in a case where the fan drive motor 5 is not driven when the count value reaches the specified value, the CPU drives the motor 42 after the drive signal of the fan drive motor 5 is input.

When the drive of the motor 42 is stopped (Step 306), that is, when the cooling mode is started, the CPU resets the timer (Step 302) and restarts counting by the counter.

By the above processing, it is also possible to periodically switch the cooling mode to the dust removal mode.

(Fourth Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a fourth mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 21 is a flowchart showing an operation of the fourth mode.

As shown in FIG. 21, the CPU judges whether the drive of the motor 42 rotated is stopped (Step 401) and judges whether the cooling mode is started.

When the drive of the motor 42 rotated is stopped and the cooling mode is started (Yes in Step 401), the CPU inputs a rotation signal from the fan drive motor 5 and starts counting of the number of rotations of the fan drive motor 5 by using the counter (Step 402).

Next, the CPU judges whether the count value of the number of rotations reaches the specified value (Step 403). The specified value is set to, for example, one million but is not limited to this.

When the count value reaches the specified value (Yes in Step 403), that is, when the number of rotations of the blade member 2 reaches the specified number of times (for example, one million times), the CPU starts the drive of the motor 42 (Step 404) and controls the movement of the opening member 30. After that, the CPU stops the drive of the motor (Step 405), resets the number of rotations, and restarts counting of the number of rotations of the fan drive motor 5 (Step 402).

By the above processing, it is also possible to periodically switch the cooling mode to the dust removal mode.

The above embodiments and modes can be variously modified.

For example, in order to ensure the movements of the opening members 30, 50, and 80 or the control of the rotation of the rotary member 130, an optical sensor or a magnetic sensor may be used.

Further, in the description with reference to FIG. 1, the laptop PC 101 is used as an example of the electronic apparatus equipped with the cooling apparatus 100, 200, 300, or 400, but the electronic apparatus is not limited to this. Examples of the electronic apparatus include a desktop PC, audiovisual equipment, a projector, a game machine, a robot apparatus, and the like.

In the above embodiments, the motors are used for driving the opening member, but a solenoid may instead be used.

Fifth Embodiment

FIG. 22 is a perspective view showing an electronic apparatus equipped with a cooling apparatus according to this embodiment. It should be noted that in the description of this embodiment, a laptop PC is used as an example of the electronic apparatus equipped with the cooling apparatus. Further, figures for the following description do not show actual dimensions in some cases to make the figures clearly understandable.

As shown in FIG. 22, a laptop PC 1101 includes an upper casing 1091, a lower casing 1092, and a hinge portion 1093 that rotatably connects the upper casing 1091 and the lower casing 1092 with each other. The upper casing 1091 includes a display portion 1094 such as a liquid crystal display and an EL (electro-luminescence) display.

The lower casing 1092 includes a plurality of input keys 1095 and a touch pad 1096 on an upper surface 1092 a and includes an outlet 1097 on a side surface 1092 b. Further, the lower casing 1092 includes an intake (not shown) on a bottom surface 1093 c, for example.

The lower casing 1092 includes a control circuit board (not shown) on which electronic circuit components such as the CPU are mounted.

A cooling apparatus 1100 is disposed so as to be close to the outlet 1097 in the lower casing 1092.

FIG. 23 is a perspective view of the cooling apparatus according to this embodiment, and FIG. 24 is an exploded perspective view of the cooling apparatus. FIG. 25 is a side cross-sectional view of the cooling apparatus.

As shown in FIGS. 23 to 25, the cooling apparatus 1100 according to the fifth embodiment includes a heat sink 1060 and a blower apparatus 1050 that generates airflow to the heat sink 1060.

The heat sink 1060 has a rectangular parallelepiped shape that is long in one direction (x-axis direction), and has a predetermined width W1 (x-axis direction) and a predetermined height H1 (z-axis direction). The heat sink 1060 includes a plurality of radiation fins 1061, and an upper plate member 1062 and a lower plate member 1063 that support the radiation fins 1061 from above and below. The plurality of radiation fins 1061 are arranged in a line at predetermined intervals along the longitudinal direction (x-axis direction) of the heat sink 1060. The airflow generated by the blower apparatus 1050 passes through gaps between the radiation fins 1061. The heat sink 1060 is formed of, for example, a metal such as aluminum and copper, but the material is not particularly limited.

It should be noted that, out of all the surfaces of the heat sink 60, a surface opposed to a blade member 1010 is referred to as an opposed surface 1060 a.

In the heat sink 1060, the upper plate member 1062 is thermally connected to a heat pipe 1070. The heat pipe 1070 is thermally connected to a heat source such as a CPU of the laptop PC 1101 through a heat spreader 1080, for example. Heat generated in the CPU is received and diffused by the heat spreader 1080 and transferred to the heat sink 1060 through the heat pipe 1070.

A method of thermally connecting the heat sink 1060 and the heat generation source such as the CPU is not particularly limited. For example, the heat sink 1060 may be directly connected with the heat spreader 1080 without the heat pipe 1070.

The blower apparatus 1050 includes the blade member 1010, a fan case 1020, and a fan drive motor 1015. The blade member 1010 is rotatable. The fan case 1020 stores the blade member 1010 therein. The fan drive motor 1015 rotates and drives the blade member 1010. In addition, the blower apparatus 1050 includes a rotary member (limiting member) 1030 and a drive mechanism 1040. The rotary member 1030 is provided between the blade member 1010 and the heat sink 1060. The drive mechanism 1040 drives the rotary member 1030.

The blade member 1010 is a centrifugal blade member, and includes a boss portion 1011 and a plurality of blade portions 1012 provided so as to extend from the boss portion 1011 in a centrifugal direction. The blade member 1010 is rotatable about a shaft extended in the z-axis direction and is rotated counterclockwise by the fan drive motor 1015. The rotation of the blade member 1010 causes the airflow to the heat sink 1060.

The fan drive motor 1015 is constituted of a stator, a magnet, and a rotor yoke (not shown), for example. The fan drive motor 1015 is electrically connected to the CPU of the laptop PC 1101, and the CPU controls the drive and stop of the fan drive motor 1015, for example.

The fan case 1020 is constituted of a case main body 1021 and a lid member 1022, for example. The case main body 1021 forms a side peripheral portion 1020 b and a lower portion 1020 c of the fan case 1020. The lid member 1022 forms an upper portion 1020 a of the fan case 1020.

On the upper portion 1020 a and the lower portion 1020 c of the fan case 1020, an upper intake 1023 and a lower intake 1024 are provided, respectively. The upper intake 1023 and the lower intake 1024 are provided in the vicinity of the center of the upper portion 1020 a and the lower portion 1020 c, respectively.

In addition to the function of storing the blade member 1010, the fan case 1020 functions as a flow path for guiding the airflow generated by the blade member 1010 to the heat sink 1060. Hereinafter, an area that mainly functions as the flow path of the airflow between the blade member 1010 and the heat sink 1060 is referred to as a flow path area 1020P of the fan case 1020 (see, FIG. 4). In addition, in the flow path area 1020P, a direction in which the airflow is directed is referred to as a flow path direction.

In the flow path area 1020P, a flow path 1026 is a rectangular flow path having a width W2 and a height H2, each of which is approximately constant in the flow path direction (y-axis direction) (cross-sectional area of the flow path=W2*H2). The width W2 and the height H2 of the flow path 1026 are relatively set with respect to the width W1 and the height H1 of the heat sink 1060 so that the width W2 and the height H2 of the flow path 1026 are approximately equal to the width W1 and the height H1 of the heat sink 1060, respectively. With this structure, the airflow that passes through the flow path 1026 is directed to the entire heat sink 1060.

The rotary member 1030 is provided between the blade member 1010 and the heat sink 1060 in the fan case 1020. That is, the rotary member 1030 is provided in the flow path area 1020P of the fan case 1020.

The rotary member 1030 has a rectangular thin-plate shape that is long in one direction (x-axis direction). A width W3 of the rotary member 1030 is approximately equal to the width W2 of the flow path 1026. It should be noted that a detailed description will be given on a height H3 of the rotary member 1030 later. The rotary member 1030 is made of a resin or a metal, for example, but the material is not particularly limited.

The drive mechanism 1040 includes a spindle 1041 connected to the rotary member 1030, an arm portion 1042 connected to one end portion of the spindle 1041, a spring 1043 connected to the arm portion 1042, and a solenoid 1044 that drives the arm portion 1042.

The spindle 1041 is rotatably disposed along the x-axis direction in the lower part of the flow path area 1020P and connected to one end portion of the rotary member 1030 in a short-side direction thereof. With this structure, the rotary member 1030 is rotatable about the spindle 1041 in the flow path area 1020P.

The arm portion 1042 is connected to one end portion of the spindle 1041 through a hole formed in the side peripheral portion 1020 b of the fan case 1020.

One end portion of the spring 1043 is connected to a spring support portion 1045 provided on the side peripheral portion 1020 b of the fan case 1020, and the other end portion of the spring 1043 is connected to the arm portion 1042.

The solenoid 1044 is electrically connected to the CPU of the laptop PC 1101, for example, and the CPU performs control to drive the spindle 1041 and the rotary member 1030 by using the arm portion 1042.

(Description of Operation)

Next, an operation of the cooling apparatus 1100 will be described. FIGS. 26A and 26B are schematic diagrams each showing the operation of the cooling apparatus 1100. FIG. 26A schematically shows a state in which the rotary member 1030 is laid down, and FIG. 26B schematically shows a state in which the rotary member 1030 is raised at a predetermined angle with respect to the flow path direction.

First, with reference to FIG. 26A, the operation in the state where the rotary member 1030 is laid down will be described.

As shown in FIG. 26A, the rotary member 1030 is generally laid down with the rotary member 1030 being parallel to the airflow and stopped. That is, the rotary member 1030 is stopped without limiting the flow path 1026.

For example, when the fan drive motor 1015 is started to drive by the control of the CPU, the blade member 1010 starts to rotate. When the blade member 1010 starts to rotate, air in the lower casing 1092 of the laptop PC 1101 is taken in the fan case 1020 through the upper intake 1023 and the lower intake 1024.

The air taken in the fan case 1020 is accelerated by the blade member 1010 in the centrifugal direction, thereby generating the airflow to the heat sink 1060. The airflow generated by the blade member 1010 passes through the flow path 1026 and is directed to the opposed surface 1060 a of the heat sink 1060.

The heat sink 1060 radiates, from the radiation fins 1061, heat transferred from the heat generation source such as the CPU through the heat spreader 1080 and the heat pipe. The air warmed in the radiation fins 1061 is exhausted to the outside of the laptop PC 1101 through the outlet 1097 of the laptop PC 1101 by the airflow generated by the blade member 1010. As a result, the CPU and the heat sink 1060 are cooled.

It should be noted that the state in which the rotary member 1030 does not limit the flow path 1026 to be released and the heat sink 1060 is cooled is referred to as a cooling mode in this specification.

Here, the air in the lower casing 1092, which is taken therein from the upper intake 1023 and the lower intake 1024, contains the dust. Accordingly, the airflow directed to the heat sink 1060 also contains the dust. For this reason, the dust adheres to and accumulates on the heat sink 1060.

FIG. 27 is a view showing a state where the dust adheres to the heat sink. FIG. 28 is an enlarged view of the heat sink in a state where the dust adheres thereto.

If the cooling mode is maintained for a long time period, the radiation fins 1061 are clogged with the dust. The dust that adheres to and accumulates on the heat sink 1060 is mainly constituted of filiform dusts. The filiform dust is likely to adhere to and accumulate on the opposed surface 1060 a of the heat sink 1060 in particular.

If the heat sink 1060 is left in the state where the dust adheres to and accumulates on the heat sink 1060, ventilation of the radiation fins 1061 is hindered, leading to deterioration of the cooling performance for the cooling apparatus 1100.

Next, with reference to FIG. 26B, the operation in the state where the rotary member 1030 is raised at the predetermined angle with respect to the flow path direction will be described.

For example, when the solenoid 1044 is driven by the control of the CPU, the rotary member 1030 is rotated about the spindle 1041. In this case, the rotary member 1030 is stopped for several seconds or several minutes with the rotary member 1030 being tilted at 90 degrees with respect to the flow path direction, for example.

When the rotary member 1030 is rotated and the flow path 1026 of the airflow is locally reduced in area (the flow path 1026 in this state will be referred to as a narrow flow path 1027 hereinafter), the airflow is changed to generate a secondary vortex on the right side of the rotary member 1030. That is, when the airflow is delivered from the narrow flow path to a wide flow path, the secondary vortex is generated due to a relationship of an expansion factor of the flow path. The cooling apparatus 1100 according to this embodiment uses the secondary vortex generated due to the relationship of the expansion factor of the flow path.

When the rotary member 1030 limits the flow path 1026 to generate the secondary vortex, the dust that adheres to the opposed surface 1060 a of the heat sink 1060 is blown away by the secondary vortex. The dust removed by the secondary vortex is caught into the secondary vortex, released from the gaps between the radiation fins 1061, and then released to the outside of the laptop PC 1101 through the outlet 1097 of the laptop PC 1101.

In this specification, the state where the rotary member 1030 limits the flow path 1026 to generate the secondary vortex and remove the dust by the secondary vortex is referred to as a dust removal mode.

As described above, in the cooling apparatus 1100 according to this embodiment, in the dust removal mode, it is possible to strongly remove the dust that adheres to the opposed surface 1060 a of the heat sink 1060 by the secondary vortex. As a result, the cooling performance of the cooling apparatus 1100 can be prevented from deteriorating.

Further, in the cooling apparatus 1100 according to this embodiment, the switching operation between the cooling mode and the dust removal mode is controlled by the CPU. Therefore, the switching between the cooling mode and the dust removal mode can be automatically performed. Accordingly, it is possible to automatically remove the dust that adheres to the heat sink 1060, with the result that the troublesome task of detaching the heat sink 1060 from the laptop PC 1101 and washing the heat sink can be eliminated.

Further, in this embodiment, the dust can be removed from the heat sink 1060 without increasing the rotation speed of the blade member 1010. Thus, an excessive increase in power consumption of the cooling apparatus 1100 can be suppressed. In addition, even when the strong airflow is difficult to be generated due to small power of the fan drive motor 1015 that rotates the blade member 1010, the dust can be removed from the heat sink 1060.

In the description with reference to FIG. 26B, the rotary member 1030 is stopped with the rotary member being tilted at 90 degrees with respect to the flow path direction in the dust removal mode. However, the state of the rotary member 1030 is not limited to this. The angle with respect to the flow path 1026 may be less than or more than 90 degrees. In other words, in the dust removal mode, it is only necessary to meet the condition that the secondary vortex is in contact with at least the opposed surface 1060 a of the heat sink. The angle at which the rotary member 1030 is raised is not particularly limited.

(Relationship Between Generation Area of Secondary Vortex and Various Parameters)

As described above, the cooling apparatus 1100 according to this embodiment partly intends to remove the dust that adheres to the heat sink 1060 by using the secondary vortex generated by the rotary member 1030. To realize this, various parameters are set so that at least the opposed surface 1060 a of the heat sink 1060 is disposed in the generation area of the secondary vortex. The various parameters include the height H2 of the flow path 1026, the height H3 of the rotary member 1030, an angle Φ by which the rotary member 1030 is rotated, the distance d between the rotary member 1030 and the opposed surface 1060 a of the heat sink, a gap a of the narrow flow path 1027, and the like.

FIGS. 29A and 29B are diagrams each showing the relationship between the generation area of the secondary vortex and the various parameters.

FIG. 29A shows the relationship between the generation area of the secondary vortex and the various parameters in a case where the rotary member 1030 is rotated by 90 degrees (Φ=90 degrees). FIG. 29B shows the relationship between the generation area of the secondary vortex and the various parameters in a case where the rotary member 1030 is rotated by 45 degrees (Φ=45 degrees).

Here, the relationship between the expansion factor of the flow path and the size of the secondary vortex will be described.

FIG. 30 is a diagram for explaining the relationship between the expansion factor of the flow path and the size of the secondary vortex. FIG. 30 shows a schematic model of enlarged airflow.

In FIG. 30, the gap of a slit is represented by b₀, a height from the bottom surface to the slit is represented by D, a re-adhesion distance is represented by x_(R), an adhesion angle is represented by θ, and a distance from an end of the narrow flow path to a virtual origin is represented by x₀. Further, in FIG. 30, a re-adhesion flow line is indicated by a dashed line, and a coordinate system with its origin being set on a center flow line is indicated by x-y axes.

The adhesion angle θ is expressed by the following expression (1) based on a momentum equilibrium condition.

cos θ=3t/2−t ³/2  (1)

t used in the expression (1) is expressed by the following expression (2).

t=tan h(σy′/(x+x ₀))  (2)

Here, in the expression (2), a diffusion coefficient is represented by σ, and an intersection point of the y axis with the re-adhesion flow line in the coordinate system with its origin being set on the center flow line is represented by y′.

Based on a geometric relationship, an expansion ratio D/b₀ is expressed by the following expression (3).

D/b ₀=σ(1/t ²−1){(1−cos θ)/3θ}−1/2  (3)

Further, a ratio x_(R)/b₀ of the re-adhesion distance x_(R) to the slit gap b₀ is expressed by the following expression (4).

x _(R) /b ₀=σ(1/t ²−1)sin θ/3θ−tan h ⁻¹ t/3t ² sin θ  (4)

By solving the simultaneous equations of the expressions (1) and (3), t and θ are obtained as functions of the expansion ratio D/b₀, and the obtained values are assigned to the expression (4). As a result, the ratio x_(R)/b₀ of the re-adhesion distance x_(R) to the slit gap b₀ can be obtained as a function of the expansion ratio D/b₀.

In this case, an approximate expression indicating a relationship between the ratio x_(R)/b₀ of the re-adhesion distance x_(R) to the slit gap b₀ and the expansion ratio D/b₀ is expressed by the following expression (5).

x _(R) /b ₀=2.22(D/b ₀)^(0.636)+0.780D/b ₀+0.939  (5)

FIG. 31 is a graph showing the relationship between the ratio x_(R)/b₀ of the re-adhesion distance x_(R) to the slit gap b₀ and the expansion ratio D/b₀.

In FIG. 31, rhomboid dots indicate numeric solutions obtained by actually solving the expressions (1), (3), and (4), and the solid line indicates the approximate expression (5) mentioned above.

Further, in FIG. 31, a shaded area indicates the generation area of the secondary vortex.

When the FIG. 29A and FIG. 30 are compared, in the case where the rotary member 1030 is rotated by the angle Φ of 90 degrees, the height H₃ of the rotary member 1030 corresponds to the height D from the bottom surface to the slit, and the gap a of the narrow flow path 1027 corresponds to the slit gap b₀. In this case, D and b₀ shown in FIG. 31 are replaced with H₃ and a, respectively, and the parameters including the height H₃, the gap a of the narrow flow path 1027, and the distance d between the rotary member 1030 and the opposed surface 1060 a of the heat sink are set so that the value in the shaded area of FIG. 31 is obtained.

In addition, when FIG. 29B and FIG. 30 are compared, in the case where the rotary member 1030 is rotated by 45 degrees, a sine component of the height H₃ of the rotary member 1030, i.e., H₃sin Φ (Φ=45 degrees) corresponds to the height D from the bottom surface to the slit, and the gap a of the narrow flow path 1027 corresponds to the slit gap b₀. In this case, the height D and b₀ shown in FIG. 31 are replaced with H₃sin45° and a, respectively, and the parameters including the height H₃, the gap a of the narrow flow path 1027, and the distance d between the rotary member 1030 and the opposed surface 1060 a of the heat sink are set so that the value in the shaded area of FIG. 31 is obtained.

As a result, the opposed surface 1060 a of the heat sink 1060 is disposed in the generation area of the secondary vortex, and therefore the dust that adheres to and accumulates on the opposed surface 1060 a of the heat sink 1060 can be appropriately removed.

(Evaluation of Dust Removal Performance)

Next, the dust removal performance of the cooling apparatus 1100 will be described in more detail.

FIG. 32 is a diagram showing a test apparatus 1081 used for evaluating the dust removal performance.

As shown in FIG. 32, the test apparatus 1081 included a hollow test apparatus main body 1082 and two sirocco fans 1083 provided inside the test apparatus main body 1082. The dimensions of the test apparatus main body 1082 were set to 300×300×300 mm. The two sirocco fans 1083 were provided on side walls of the test apparatus main body 1082 so as to be opposed to each other.

Inside the test apparatus main body 1082, a cotton waste 1085 likened to the dust and the cooling apparatus 1100 were disposed. Over the cooling apparatus 1100, a net 1084 was covered for preventing a large dust ball from getting thereinto.

First, the sirocco fans 1083 were driven for thirty seconds with the blade member 1010 of the cooling apparatus 1100 being rotated (Step 1).

Next, the rotary member 1030 was rotated by 45 degrees with respect to the flow path direction and maintained for ten seconds, and thereafter the rotary member 1030 was returned to the position at 0 degree with respect to the flow path direction and maintained for ten seconds. This operation was repeated twice (Step 2).

After that, Step 1 and Step 2 were repeated ten times.

It should be noted that in a cooling apparatus used for comparison (cooling apparatus having no dust removal performance), the rotary member 1030 was maintained at 0 degree with respect to the flow path direction without being rotated in Step 2 above.

FIG. 33 is a diagram showing comparison among flow path resistances of the heat sink prior to the test, in the case where the dust removal performance was provided, and in the case where the dust removal performance was not provided.

In FIG. 33, a vertical axis represents a pressure difference ΔP (Pa) between the airflow before passing through the heat sink 1060 and the airflow after passing through the heat sink 1060, and a horizontal axis represents an air volume Q (m³/min) of the airflow passing through the heat sink 1060.

In FIG. 33, a curved line obtained by linking triangular dots indicates the flow path resistance prior to the test. A curved line obtained by linking square dots indicates the flow path resistance in the case where the dust removal performance was provided, that is, the case where the rotary member 1030 was driven. Further, a curved line obtained by linking rhomboid dots indicates the flow path resistance in the case where the dust removal performance was not provided, that is, the case where the rotary member 1030 was not driven.

It should be noted that approximate expressions (6), (7), and (8) of the curved lines prior to the test, in the case where the dust removal performance was provided, and in the case where the dust removal performance was not provided shown in FIG. 33 are as follows, respectively.

ΔP=4.82×10³ Q ²+2.54×10² Q  (6)

ΔP=4.88×10³ Q ²+2.62×10² Q  (7)

ΔP=7.71×10³ Q ²+5.42×10² Q  (8)

As shown in FIG. 33, the flow path resistance of the heat sink 1060 in the case where the dust removal performance was provided was markedly smaller than that in the case where the dust removal performance was not provided. In addition, the flow path resistance of the heat sink 1060 in the case where the dust removal performance was provided was almost the same as that prior to the test.

As shown in FIG. 33, it was found that, in the cooling apparatus 1100 according to this embodiment, the dust causing the flow path resistance of the heat sink 60 was desirably removed. In other words, the cooling apparatus 1100 according to this embodiment has high dust removal performance.

The state where the dust adhered to the heat sink 1060 not having the dust removal performance and the state where the dust adhered to the heat sink 1060 having the dust removal performance were observed. As a result, in the heat sink 1060 not having the dust removal performance, the entire radiation fins 1061 on the opposed surface 1060 a were clogged with the dust, which merely allowed the gaps between the radiation fins in the center of the heat sink 1060 to be partly seen. In contrast, in the heat sink 1060 having the dust removal performance, the dust hardly adhered to the opposed surface 1060 a, and a little dust just adhered to the both sides of the heat sink.

(Fifth Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a fifth mode regarding timing of switching between the cooling mode and the dust removal mode.

FIG. 34 is a flowchart showing an operation of the fifth mode regarding the mode switching timing.

As shown in FIG. 34, the CPU of the laptop PC judges whether a drive start signal of the fan drive motor 1015 is input (Step 1101). When the drive start signal is not input (No in Step 1101), the CPU judges again whether the drive start signal of the fan drive motor 1015 is input.

When the drive start signal of the fan drive motor 1015 is input (Yes in Step 1101), the CPU starts to drive the fan drive motor 1015 (Step 1102). When the drive of the fan drive motor is started, the rotation of the blade member 1010 is started, and the airflow is generated to the heat sink 1060.

When starting the drive of the fan drive motor 1015, the CPU starts to drive the solenoid 1044 subsequently (Step 1103). When the solenoid 1044 is driven, the rotary member 1030 is rotated by 45 degrees with respect to the flow path direction. The rotation of the rotary member 1030 locally makes the flow path 1026 smaller, which generates the secondary vortex. The secondary vortex blows away the dust that adheres to the opposed surface 1060 a of the heat sink 1060 to remove the dust (dust removal mode).

After several seconds or several minutes later since the start of the drive of the solenoid 1044, the CPU stops the drive of the solenoid 1044 (Step 1104). When the drive of the solenoid 1044 is stopped, the rotary member 1030 is returned to the position at 0 degree with respect to the flow path direction, thereby causing the rotary member 1030 to be parallel to the airflow. In this case, the heat sink 1060 is cooled (cooling mode).

When the CPU stops the drive of the solenoid 1044, the processing returns to Step 1101 again, and the steps subsequent to Step 1101 are repeated.

By the above processing, it is possible to periodically switch the cooling mode to the dust removal mode, with the result that the dust can be removed from the heat sink before the dust that adheres to the heat sink 60 accumulates thereon and causes clogging of the radiation fins.

(Sixth Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a sixth mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 35 is a flowchart showing an operation of the sixth mode regarding the mode switching timing.

As shown in FIG. 35, the CPU judges whether a stop notice signal of the fan drive motor 1015 is input (Step 1201). When the stop notice signal is not input (No in Step 1201), the CPU judges again whether the stop notice signal is input. In this case, the rotary member 1030 is not rotated, and the heat sink 1060 is cooled (cooling mode).

When the stop notice signal of the fan drive motor 1015 is input (Yes in Step 1201), the CPU does not immediately stop the fan drive motor 1015 but starts to drive the solenoid 1044 (Step 1202). When the drive of the solenoid 1044 is started, the rotary member 1030 is rotated, and thus the secondary vortex is generated. As a result, the dust that adheres to the opposed surface 1060 a of the heat sink 1060 is blown away and removed therefrom (dust removal mode).

After several seconds or several minutes later since the start of the drive of the solenoid 1044, the CPU stops the drive of the solenoid 1044 (Step 1203). When the drive of the solenoid 1044 is stopped, the rotary member 1030 is returned to the position at 0 degree with respect to the flow path direction, thereby causing the rotary member 1030 to be parallel to the airflow.

After stopping the drive of the solenoid 1044, the CPU stops the drive of the fan drive motor 1015 (Step 1204).

By the above processing, it is also possible to periodically remove the dust from the heat sink 1060, and therefore the same effect as the fifth mode can be obtained.

(Seventh Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on a seventh mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 36 is a flowchart showing an operation of the seventh mode.

The CPU judges whether the drive of the solenoid 1044 is stopped (Step 1301). That is, the CPU judges whether the dust removal mode is switched to the cooling mode and the cooling mode is started. When the drive of the solenoid 1044 is stopped (Yes in Step 1301), the CPU sets a timer of a counter to be on and starts counting of count values generated at predetermined intervals. For the counter, a counter dedicated to the cooling apparatus 1100 may be used, or a counter equipped to the electronic apparatus such as the laptop PC 1101 may be used.

Next, the CPU judges whether the count value reaches a specified value (Step 1303). The specified value corresponds to a certain time period, e.g., one week, but is not limited to this.

When the count value reaches the specified value (Yes in Step 1303), that is, when the certain time period (e.g., one week) elapses from when the cooling mode is started, the CPU judges whether the fan drive motor 1015 is driven (Step 1304).

When the fan drive motor 1015 is driven (Yes in Step 1304), the CPU starts to drive the solenoid 1044 (Step 1305). In this case, the rotary member 1030 is rotated, thereby generating the secondary vortex. As a result, the dust is removed from the opposed surface 1060 a of the heat sink 1060 (dust removal mode).

After several seconds or several minutes later since the start of the drive of the solenoid 1044, the CPU stops the drive of the solenoid 1044 (Step 1306). In this case, the rotary member 1030 is returned to the position at 0 degree with respect to the flow path direction, thereby cooling the heat sink 1060 (cooling mode).

On the other hand, in a case where the fan drive motor 1015 is not driven when the count value reaches the specified value (No in Step 1304), the CPU judges whether a drive signal of the fan drive motor 1015 is input (Step 1307).

When the drive signal of the fan drive motor 1015 is input (Yes in Step 1307), the CPU drives the fan drive motor 1015 (Step 1308) and thereafter starts the drive of the solenoid 1044 (Step 1305). That is, in a case where the fan drive motor 1015 is not driven when the count value reaches the specified value, the CPU drives the solenoid 1044 after the drive signal of the fan drive motor 1015 is input.

When the drive of the solenoid 1044 is stopped (Step 1306), that is, when the cooling mode is started, the CPU resets the timer (Step 1302) and restarts counting by the counter.

By the above processing, it is also possible to periodically switch the cooling mode to the dust removal mode.

(Eighth Mode Regarding Timing of Switching Between Cooling Mode and Dust Removal Mode)

Next, a description will be given on an eighth mode regarding timing of switching between the cooling mode and the dust removal mode. FIG. 37 is a flowchart showing an operation of the eighth mode.

As shown in FIG. 37, the CPU judges whether the drive of the solenoid 1044 is stopped (Step 1401) and judges whether the cooling mode is started.

When the drive of the solenoid 1044 is stopped and the cooling mode is started (Yes in Step 1401), the CPU inputs a rotation signal from the fan drive motor 1015 and starts counting of the number of rotations of the fan drive motor 1015 by using the counter (Step 1402).

Next, the CPU judges whether the count value of the number of rotations reaches the specified value (Step 1403). The specified value is set to, for example, one million but is not limited to this.

When the count value reaches the specified value (Yes in Step 1403), that is, when the number of rotations of the blade member 1010 reaches the specified number of times (for example, one million times), the CPU starts the drive of the solenoid 1044 (Step 1404) and rotates the rotary member 1030. After that, the CPU stops the drive of the solenoid 1044 (Step 1405), resets the number of rotations, and restarts counting of the number of rotations of the fan drive motor 1015 (Step 1402).

By the above processing, it is also possible to periodically switch the cooling mode to the dust removal mode.

(Various Modified Examples)

The above embodiments can be variously modified.

For example, in order to ensure the control of the angle by which the rotary member 1030 is rotated, an optical sensor or a magnetic sensor may be used.

In the above embodiments, the drive mechanism 1040 that drives the rotary member 1030 includes the arm portion 1042, the spring 1043, and the solenoid 1044. However, the structure of the drive mechanism 1040 is not limited to this. For example, as the drive mechanism 1040 for driving the rotary member 1030, a motor may be used instead of the solenoid. In this case, in order to ensure the control of the angle by which the rotary member 30 is rotated, a stepper motor may be used.

In the above embodiments, the CPU of the laptop PC controls the drives of the fan drive motor 1015 and the solenoid 1044, but the structure is not limited to this. A CPU dedicated to the cooling apparatus 1100 may be provided and may control the drives of the fan drive motor 1015 and the solenoid 1044.

In the description with reference to FIG. 22, the laptop PC 1101 is used as an example of the electronic apparatus equipped with the cooling apparatus 1100, but the electronic apparatus is not limited to this. Examples of the electronic apparatus include a desktop PC, audiovisual equipment, a projector, a game machine, a robot apparatus, and others.

It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims. 

1. A cooling apparatus, comprising: a heat sink; a blower mechanism having a blower opening that has a predetermined area and is opposed to the heat sink; an opening member having a first opening that has an area smaller than the area of the blower opening; and a movement mechanism to move the opening member to perform switching between a first state and a second state, the first state being a state in which the first opening is disposed between the blower opening and the heat sink, the second state being a state in which the first opening is removed from between the blower opening and the heat sink.
 2. The cooling apparatus according to claim 1, wherein the opening member further has a second opening having an area equal to the area of the blower opening, and wherein the second state is a state in which the second opening is opposed to the blower opening.
 3. The cooling apparatus according to claim 2, wherein the opening member is a band-like member having a longitudinal direction, wherein the first opening and the second opening are formed in the band-like member in a line along the longitudinal direction of the band-like member, and wherein the movement mechanism moves the band-like member along the blower opening in the longitudinal direction.
 4. The cooling apparatus according to claim 3, wherein the movement mechanism includes a first shaft connected to an end portion of the band-like member and capable of rolling up and rolling out the band-like member, a second shaft disposed so that the first shaft and the second shaft sandwich the blower opening, connected to another end portion of the band-like member, and capable of rolling up and rolling out the band-like member, and a drive source to rotate and drive the first shaft and the second shaft.
 5. The cooling apparatus according to claim 3, wherein the band-like member is annular, and wherein the movement mechanism includes a plurality of shafts to support the band-like member while rotating the band-like member around the blower mechanism with the plurality of shafts being provided around the blower mechanism, and a drive source to rotate and drive at least one of the plurality of shafts.
 6. The cooling apparatus according to claim 1, wherein the opening member is a plate-like member having a longitudinal direction, and wherein the movement mechanism moves the plate-like member along the blower opening in the longitudinal direction.
 7. The cooling apparatus according to claim 6, wherein the plate-like member includes a rack gear in the longitudinal direction, and wherein the movement mechanism includes a pinion engaged with the rack gear, and a drive source to rotate and drive the pinion.
 8. The cooling apparatus according to claim 1, further comprising: a control means for controlling a movement of the opening member by the movement mechanism so that the second state is periodically switched to the first state.
 9. The cooling apparatus according to claim 8, wherein the blower mechanism further includes a blade member that generates airflow flown out from the blower opening by rotation thereof, and wherein the control means controls the movement of the opening member so that the second state is switched to the first state when one of start and stop of the rotation of the blade member is performed.
 10. The cooling apparatus according to claim 8, wherein the blower mechanism further includes the blade member that generates airflow flown out from the blower opening by rotation thereof, the cooling apparatus further comprising: a rotation counting means for counting a number of rotations of the blade member; and a rotation count judging means for judging whether the number of rotations counted reaches a specified count, and wherein the control means controls the movement of the opening member so that the second state is switched to the first state when the number of rotations reaches the specified count.
 11. The cooling apparatus according to claim 8, further comprising: a time counting means for counting a time period that elapses from when the first state is switched to the second state; and a time judging means for judging whether the time period counted reaches a specified time period, wherein the control means controls the movement of the opening member so that the second state is switched to the first state when the time period reaches the specified time period.
 12. A cooling apparatus, comprising: a heat sink; a blower mechanism having a blower opening that has a predetermined area and is opposed to the heat sink; a rotary member including a shield portion that limits the area of the blower opening, the rotary member being rotatable and disposed between the heat sink and the blower opening; and a rotary mechanism to rotate the rotary member to perform switching between a first state and a second state, the first state being a state in which the area of the blower opening is limited by the shield portion, the second state being a state in which the area of the blower opening is free of being limited by the shield portion.
 13. The cooling apparatus according to claim 12, wherein the blower opening has a longitudinal direction, and wherein the rotary member is rotatable about a shaft extended along the longitudinal direction.
 14. The cooling apparatus according to claim 13, wherein the rotary member includes a first rotary member and a second rotary member that are disposed while the blower opening being disposed therebetween.
 15. An electronic apparatus, comprising: a heat generation source; and a cooling apparatus including a heat sink that radiates heat transferred from the heat generation source, a blower mechanism having a blower opening that has a predetermined area and is opposed to the heat sink, an opening member having a first opening that has an area smaller than the area of the blower opening, and a movement mechanism to move the opening member to perform switching between a first state and a second state, the first state being a state in which the first opening is disposed between the blower opening and the heat sink, the second state being a state in which the first opening is removed from between the blower opening and the heat sink.
 16. An electronic apparatus, comprising: a heat generation source; and a cooling apparatus including a heat sink that radiates heat transferred from the heat generation source, a blower mechanism having a blower opening that has a predetermined area and is opposed to the heat sink, a rotary member that includes a shield portion to limit the area of the blower opening and is rotatable and disposed between the heat sink and the blower opening, and a rotary mechanism to rotate the rotary member to perform switching between a first state and a second state, the first state being a state in which the area of the blower opening is limited by the shield portion, the second state being a state in which the area of the blower opening is free of being limited by the shield portion.
 17. A blower apparatus, comprising: a blower mechanism having a blower opening that has a predetermined area; an opening member having a first opening that has an area smaller than the area of the blower opening; and a movement mechanism to move the opening member to perform switching between a first state and a second state, the first state being a state in which the first opening is disposed in front of the blower opening, the second state being a state in which the first opening is removed from the front of the blower opening.
 18. A blower apparatus, comprising: a blower mechanism having a blower opening that has a predetermined area; a rotary member including a shield portion that limits the area of the blower opening, the rotary member being rotatable and disposed in front of the blower opening; and a rotary mechanism to rotate the rotary member to perform switching between a first state and a second state, the first state being a state in which the area of the blower opening is limited by the shield portion, the second state being a state in which the area of the blower opening is free of being limited by the shield portion.
 19. A cooling apparatus, comprising: a heat sink having a surface to which airflow is directed; a blade member to generate the airflow to the surface; a flow path member to form a flow path through which the airflow is guided from the blade member to the heat sink; a limiting member capable of limiting the flow path; and a drive mechanism to drive the limiting member so that switching between a first state and a second state is performed, the first state being a state in which the flow path is free of being limited by the limiting member, the second state being a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface.
 20. The cooling apparatus according to claim 19, further comprising: a control means for controlling the drive mechanism so that the first state is periodically switched to the second state.
 21. The cooling apparatus according to claim 20, wherein the blade member generates the airflow by rotation thereof, and wherein the control means controls the drive mechanism so that the first state is switched to the second state when the rotation of the blade member is started.
 22. The cooling apparatus according to claim 20, wherein the blade member generates the airflow by rotation thereof, and wherein the control means controls the drive mechanism so that the first state is switched to the second state when the rotation of the blade member is stopped.
 23. The cooling apparatus according to claim 20, wherein the blade member generates the airflow by rotation thereof, the cooling apparatus further comprising: a rotation counting means for counting a number of rotations of the blade member; and a rotation count judging means for judging whether the number of rotations counted reaches a specified count, and wherein the control means controls the drive mechanism so that the first state is switched to the second state when the number of rotations reaches the specified count.
 24. The cooling apparatus according to claim 20, further comprising: a time counting means for counting a time period that elapses from when the second state is switched to the first state; and a time judging means for judging whether the time period counted reaches a specified time period, wherein the control means controls the drive mechanism so that the first state is switched to the second state when the time period reaches the specified time period.
 25. An electronic apparatus, comprising: a heat generation source; and a cooling apparatus including a heat sink that has a surface to which airflow is directed and radiates heat transferred from the heat generation source, a blade member to generate the airflow to the surface, a flow path member to form a flow path through which the airflow is guided from the blade member to the heat sink, a limiting member capable of limiting the flow path, and a drive mechanism to drive the limiting member so that switching between a first state and a second state is performed, the first state being a state in which the flow path is free of being limited by the limiting member, the second state being a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface.
 26. A blower apparatus, comprising: a blade member to generate airflow to a surface of a heat sink, the heat sink having the surface to which the airflow is directed; a flow path member to form a flow path through which the airflow is guided from the blade member to the heat sink; a limiting member capable of limiting the flow path; and a drive mechanism to drive the limiting member so that switching between a first state and a second state is performed, the first state being a state in which the flow path is free of being limited by the limiting member, the second state being a state in which the flow path is limited by the limiting member to generate a vortex so that the vortex is contacted with the surface. 